Project Manager error--copy & collect

Question

We are trying to collect files & copy to new location through Project Manager in PPro CS5.  We exclude unused clips and made sure the destination has plenty of free space.
On 3 separate projects on 2 different Windows 7 machines, we have the same problem.  It starts working, then eventually gives us an error "An unknown error occurred during the Project Manager operation.  Please save your project and retry the operation."  We've tried saving to a different destination, closing PPro, opening and trying again---all with the same result.  It consistently gives us the error, but seems to give us the error at different progress points.
I've seen other posts that mention similar problems and solutions, but since this is happening to us across multiple machines and projects it appears that ours is a different problem.  Our projects are fairly simple, no major effects, just some .mts, .m2t, and jpeg files.  This process used to work for us without a problem. Please advise.

Answer 1

In practice, if you have moved several files from location A to location B, when you open the project, Premiere throws up a dialogue box asking for the location of one of the files.  If you locate that file, Premiere automatically links to all the rest of the files you moved to B.
There is also a useful little check box in the dialogue box, which if ticked shows only exact file name matches.  This did not always work in CS4, but seems fine in CS5.
It is better to do the re-linking at this stage because if you do not, once the project is open, you have to re-link each asset individually, which is a pain.
In the days of SD, with avis and much smaller hard dirives, the crate a trimmed project function was useful as you could save only those parts of captured clips that you needed, but with the more highly compressed mpeg etc files, Premiere no longer trims the captured video, but merely copies the entire file to a new location, as far as I can see.