first file is 1.37 GB recorded in 1920x1080 at 60fps
the second is 1.52 GB recorded at 1280x720 at 30 fps

So i guess the settings werent the same my mistake

Can you run each of the files through Mediainfo (free download), select the text view, and post the results? That will tell us the differences.

THIS IS MY VIDEO (THE ONE THAT WON'T OPEN)

General
Complete name : G:\TL2 050213.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 1.38 GiB
Duration : 2h 27mn
Overall bit rate mode : Constant
Overall bit rate : 1 335 Kbps
Encoded date : UTC 2013-05-03 00:27:07
Tagged date : UTC 2013-05-05 07:58:43
Writing application : Open Broadcaster Software v0.51b

Video
ID : 2
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.2
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Muxing mode : Container profile=High@3.1
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 2h 27mn
Source duration : 2h 27mn
Bit rate mode : Constant
Bit rate : 1 000 Kbps / 1 000 Kbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 60.000 fps
Minimum frame rate : 58.824 fps
Maximum frame rate : 62.500 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.008
Stream size : 1.03 GiB (75%)
Source stream size : 1.03 GiB (75%)
Writing library : x264 core 130 r2274 c832fe9
Encoding settings : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=6 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=cbr / mbtree=1 / bitrate=1000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=1000 / vbv_bufsize=1000 / nal_hrd=cbr / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2013-05-03 00:27:07
Tagged date : UTC 2013-05-03 00:27:07
mdhd_Duration : 8861649

Audio
ID : 1
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Codec ID : 6B
Duration : 2h 27mn
Source duration : 2h 27mn
Bit rate mode : Constant
Bit rate : 320 Kbps
Channel(s) : 2 channels
Sampling rate : 44.1 KHz
Compression mode : Lossy
Stream size : 338 MiB (24%)
Source stream size : 338 MiB (24%)
Writing library : LAME3.99.5
Encoded date : UTC 2013-05-03 00:27:07
Tagged date : UTC 2013-05-03 00:27:07

This is the read out for the video that WILL OPEN


General
Complete name : G:\Trial & Error Pilot 3.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 1.53 GiB
Duration : 2h 17mn
Overall bit rate : 1 592 Kbps
Encoded date : UTC 2013-05-03 00:27:02
Tagged date : UTC 2013-05-03 00:27:02
Writing application : Open Broadcaster Software v0.50b

Video
ID : 2
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 2h 17mn
Source duration : 2h 17mn
Bit rate : 1 487 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 30.000 fps
Minimum frame rate : 29.412 fps
Maximum frame rate : 30.303 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.054
Stream size : 1.43 GiB (93%)
Source stream size : 1.43 GiB (93%)
Writing library : x264 core 130 r2274 c832fe9
Encoding settings : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=6 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=crf / mbtree=1 / crf=25.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=2000 / vbv_bufsize=2800 / crf_max=0.0 / nal_hrd=none / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2013-05-03 00:27:02
Tagged date : UTC 2013-05-03 00:27:02
mdhd_Duration : 8253566

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 2h 17mn
Source duration : 2h 17mn
Bit rate mode : Constant
Nominal bit rate : 96.0 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Compression mode : Lossy
Source stream size : 94.4 MiB (6%)
Language : English
Encoded date : UTC 2013-05-03 00:27:02
Tagged date : UTC 2013-05-03 00:27:02
mdhd_Duration : 8253510

Apparently Vegas is not the only one to struggle with the isom codec, which is from Kodak cameras. There may be some hints for you here:

http://forum.doom9.org/showthread.php?t=156591

I suspect the problem relates to these files being created for streaming in Open Broadcaster. I've had issues with vision encoded using AVC as these files are.
Most likely the real problem is the frequency of I frames. The fewer the I frames the more buffering Vegas has to do.
In my case I could get most of the files into Vegas and they would only just play but the thumbnails were garbage. One really problematic set of files I found I could get only one at a time into V11, try to 2 and I'd have to restart V11. So, I very gingerly put one at a time on the T/L and rendered out to AVC using the Sony encoder. Back in V9 they edited just fine.

Bob.

The file that won't open was encoded with MP3 audio. That's the reason.
Just demux in AVIDemux (the audio to PCM) and bring the separate files into Vegas.

Both files were encoded with x264, and contain a lot of high profile "stuff" that tends to make them sluggish on the timeline. Main profile encoding is just fine for this.

I have tried using different converters to see if switching file formats would fix the problem but sadly it hasn't.

I said demux, not convert.
Upload the file somewhere, and we will have a look.

omg, ty so much, i didnt see your post before. Ok ill try that

Ok i am looking at the menu option right now, when you say Dumux i assume you mean Dummy Muxer output format?

Upload the file somewhere.
I'll do it for you.

What software do you use for demuxing? The Womble tools I have been using only work on mpeg2 and I need to find something that works for more formats.

AVIDemux has been (finally) updated.
I always try it first, then go on to other tools if it doesn't do what I want.
For simple pre-processing for Vegas ingestion, it "usually" works.

I am uploading the video to youtube. I have tried using the AVIDmux software but it keeps crashing on me. I'm sad now