Big slowdown when restarting ASP.NET application

I found a big slowdown when I make some changes to sources and ASP.NET is recompiling and restarting an application. I noticed that cmdagent.exe takes 50% of my CPU (Centrino Core Duo I) and “time to start” is 150 seconds. When I kill cmdagent.exe, it is about 50 seconds.
Currently I have CPF, my feeling is, that it was OK before going to latest update.