I've used Vegas a few weeks, and it just recently started acting up for reasons unknown.

I upload videos onto Youtube and there is a limit of 100 MB.
I use the exact same procedure as I've always used and recently vegas has been wrong about the estimated size of the video.

Example:
About three weeks ago I made an 8 minute long video about 55 MB. Vegas's estimated size was exactly 55 MB.

But just yesterday and today, I made a 5 minute long video and Vegas estimated 37 MB. When everything was complete and I started uploading it to Youtube, it was 130 MB?

I have followed the exact same procedures as I did in the beginning, have used the exact same CD's, same wmv file, everything, but now my videos are amost tenfold MB higher than what Vegas estimates?

Why is this and how can I fix it?

Thanks in advance.