Also Joel has experienced situations when AOLserver's system encoding wasn't set to utf-8. I've never experienced this with either 4.0.0 or 4.0.2. AOLserver 3.3.1ad13 had this at the end of modules/tcl/init.tcl:
encoding system [ns_config ns/server/[ns_info server] SystemEncoding utf-8]
so that the Tcl system encoding was set to ns/server/$server/SystemEncoding, defaulting to utf-8. This patch was in the ad13 part.