Well, yes, ashSimpl.exe is the "Simple User Interface" scanner - but was it frozen? Previously, were you also running a on-demand scan? (I wasn't sure if you're talking about the resident protection maybe?)
If it wasn't frozen now, I'd simply suggest to wait until the next lock-up occurs and then note the exact name of the process and post it here.
Btw, how long did you wait until you claimed the program to be frozen? Were you able to move the window with your mouse, for example (when it was "frozen")?