I've seen the name resolver's semaphore get locked without being released. That results in the behavior Derek describes. I have no idea how this happens, but you can solve it by enterring a debugger and signalling the semaphore that is being waited on.
Note, this fix may end up screwing up your image later, though, in case there really is some process blocked inside a name lookup and it finally returns. So this is more of a temporary fix, and you should probably reload everything in a new image. Project fileouts can make this very smooth.
-Lex