I just wondered if anyone knew why past frames sometimes pop up later in a project timeline where they don't belong?

I never had this problem in earlier versions of Vegas, but it has happened in Vegas 8 several times to me now.

How weird is this?!?!?!?!?

I'm doing an instructional video, and I had a shot of a circuit board. I wanted to superimpose some information about components, so I created a timeline above the main timeline and masked in component identification graphics.
I later changed my mind and did an animation instead, and I deleted the whole sequence from my timeline. Everything seemed fine.
When the project was done, I rendered it to a cineform master. And on double checking it, saw that the objects I had masked in (a sequence I erased) now appeared LATER in the video on top of another sequence, yet I see them no where on the time line.

How can this be, and can I get rid of them!?!

With Vegas 8, I've several times had a spurious frame turn up somewhere far out of place in a project, and I just deleted the spurious frame (weird, but fixable). But I can't delete frames in this case because they appear over other footage I need.

Am I doing something karmically wrong to incur these ghosts!?! :-)

Thanks!

A couple things I'd try are:

1. Reduce the "Ram Render" amount to a small value (in the 16 to 128 range)
2. Reboot before rendering

Thanks. That did it, I think... I also reloaded suspicious clips...