See if you can find a tool that monitors the files that are open to let you check which files are the problem. I have one but it's for RISC OS which is unlikely to help you...
A potential problem here is that the Squeak idea of a FileStream doesn't map very tightly to the OS' idea. If you open the same file n times for example (and it's platform dependent to some degree) and close it n-1 times then obviously the OS will consider it open and behave somewhat differently than if it is _really_ closed.
tim -- Tim Rowledge, tim@sumeru.stanford.edu, http://sumeru.stanford.edu/tim Remember the good old days, when CPU was singular?