The debugged code is running in a Websphere 6.0.2 instance (IBM jdk 1.4). In 7905, the debugger hangs waiting after just a few operations (say hit a breakpoint, step over a couple of times, resume program). The -Didea.debugger.keep.temp.objects=false option is set in the vmoptions file (in order to work around the ibm jdk crashing problem). 7.0.3 was showing this problem, occasionally (rare enough to not be a real problem). Build 7905, however, gets in this state almost every debug session.