This may be unconnected with your problem, but i have had a couple of crashes where ATC.dll was the faulting module.
Cannte remebmer exactly now but something to do with the default atc causing a problem when one of your radio frequencies corresponds to an ATIS frequency in the vicinity. The key to this crash was it occured after attempting to contact the next centre/approach.
Do a google search for "pfe crash atis".
Peter
Thanx Peter, you may have something here, this is when I experience the hang, always on approach and I think always when I try to contact center or change freqs. What ever it is, it is a conflict which has been a problem on two different computer systems. So think you may be right,