Hi,
unfortunately, this is a known problem, but without a known answer. I am not a windows user, so I lack the ability to properly debug this - any input on this is welcome. However, I have some observational data that might help you a little bit. First of all, it would be nice, if you could tell us which hardware the respecting machines run, it seems to make a difference. My experience is, that Ltk with clisp seems to run on single-cpu machines, but fails on all multi-cpu machines I tried. Ltk with sbcl seems to run on all machines, but as I said, I did not do in-depth investigations.
Peter