CCS v5, same problem. Using SysInternals Process Explorer, I have captured the stack of the one of the offending threads. Sorry for the poor formatting - the forum doesn't seem to like cut and paste from Notepad++.
ntoskrnl.exe!KeWaitForMultipleObjects+0xc0antoskrnl.exe!ExfReleasePushLock+0x8ecntoskrnl.exe!PoStartNextPowerIrp+0x331ntoskrnl.exe!PoStartNextPowerIrp+0x17e7ntoskrnl.exe!PoStartNextPowerIrp+0x1a97jvm.dll!AsyncGetCallTrace+0x1059fjvm.dll!_JVM_EnqueueOperation@20+0x5de21jvm.dll!_JVM_EnqueueOperation@20+0x3df44jvm.dll+0x844fjvm.dll!_JVM_EnqueueOperation@20+0x3cb6fkernel32.dll!WaitForSingleObjectEx+0x43jvm.dll!_JVM_EnqueueOperation@20+0x3e1a3jvm.dll+0x10dfjvm.dll!_JVM_EnqueueOperation@20+0x5de21jvm.dll!_JVM_EnqueueOperation@20+0x5de30jvm.dll!_JVM_FindSignal@4+0x71b38jvm.dll!_JVM_EnqueueOperation@20+0x5de21jvm.dll!_JVM_EnqueueOperation@20+0x5de30jvm.dll!_JVM_FindSignal@4+0x71b38jvm.dll!_JVM_EnqueueOperation@20+0x5de21ntdll.dll!RtlQueryEnvironmentVariable+0x241jvm.dll!_JVM_FindSignal@4+0x2f80djvm.dll!AsyncGetCallTrace+0x27c8cjvm.dll!_JVM_FindSignal@4+0x50b61jvm.dll!AsyncGetCallTrace+0x28224