Wait... No, actually. The dubbed mini-DV is doing the same thing.
Are you saying that your ORIGINAL tape does this?
If so... there's NO WAY to correct this.
If you do a DUB... you're just duplicating what you've got.
I just did a VHS-C Dub to DVCam... and the customer wanted to know why it didn't look any better. Same thing in your case... what goes in is what comes out. (just in a different format.)
Ignore the bitrate thing, bad info there.
Who did this dub?
Sounds to me like they did it using a VCR that could cope with DVCAM. One difference with DVCAM is the tape runs faster and although a lot of gear that isn't branded DVCAM will play the tape you can get this problem, the transport has a go at keeping up but looses the plot from time to time.
Can you get the original DVCAM tape?
Once you have that you can ingest straight into Vegas with any number of Sony decks, the most popular being the DSR-11. The data coming off the tape is almost identical (just a minor difference with locked audio) to what comes off DV.
Reason I ask is I'm pretty certain the DV dub is quite useless and who ever did the dub isn't much better. Anyone with half a clue about making dubs knows you check a dub in at least one place, preferably three.
The other very remote possibility is that the VCR used to record the dub was out of alignment. You might get better results playing the DV tape out in another deck. I don't hold much hope for this though as if that was problem you'd be getting dropouts rather than skipping.
Is it possible the person who duped this for you made you a DVCAM clone? This would definately play back the way you described if your playback device doesn't support DVCAM. If the person who made the dub used a firewire between decks, instead of an analog connection, the resulting tape would most likely be DVCAM, as firewire transmits only digital information which most decks won't transcode to another format.
BTW, if this person checked the tape on playback, it would seem fine, because it would be your deck having the issue with playback.