Robert's problem sounds like a FreeBSD issue with AOLserver, perhaps? It sounds as though file handles might not be properly reclaimed after threads end execution, that kind of thing.
It would be good to isolate the problem, if you can. Forget the ACS for the moment, and put up an AOLserver to a different pageroot.
Try simple .html, .adp, and .tcl files and see if you get the same problem. If so, talk to the folks at aolserver.com about it.
As far as Linux goes, apparently 2.0.* had some problems in this area that have been cleaned up for 2.2.* kernels. I've seen discussion of it in newsgroups between folks who've never heard of AOLserver, much less the ACS.
