scrollbar hangs 21.4.11 under Win2000

Dear developers, switching from Windows NT to 2000 a strange problems shows up: I can scroll without problems with the wheel, but as soon as I hit the scrollbar, xemacs doesn't respond to anything any more, it simply hangs (and doesn't recover, at least not within 30 minutes)...doesn't seem to depend on anything else. As I formerly only worked on Linux and only recently need to use Windows (thanks a lot for the Windows port :-)))), I unfortunately do not know how to get further information about what really happens; I can only give the following information about my system: Xemacs 21.4.11 (both native + cygwin show the same problem) Win2000 (dual processor machine) USB wheel mouse (I saw an older message with similar problems with lazy-lock: in my case, it hangs even without lazy-lock, font-lock,...) Please let me know if I can do anything else! Regards, Angelika Hofmann