Any more details on this?
Definitely a DPC latency issue here. As soon as I start AIS FW, DPC shoots to steady 16000us+ if utorrent is downloading and goes back to "normal" as soon as I kill FW (just using the start/stop FW setting in Avast is enough).
Requirement is that utorrent + FW has been running for some time (the problem doesn't kick in immediately, even if utorrent is running at full speed -> something goes to "spinlock" state in FW only after some time).
AIS build 1203, Win7 x64 Home, AMD X2 4400+, 4GB.