Animation key-frames won't stay put when I save and re-load a .vf file.

Hello. I've been using Sony Vegas Movie Studio HD 11 for some time now, and overall, it's worked well. However, there's one thing that's been happening every time I save a file as a .vf and re-open it later on.

If I've got any text media and have them fade, change colour, move, basically animate in any way using keyframes, when I save and re-load the file, the keyframes have gone from their original location to a position around eight times away from the original time.

This happens every time I save a .vf file, and makes making any sort of animation a pain since if the program crashes for some trivial reason (eg trying to enable shadows on text), I have to re-do the entire thing again. Has anyone else had this happen to them, and is there a way to stop this from happening? I'm using Windows 7 64-bit, if that's any help.