Hmm, can you post what your system spec is ? CPU/memory/etc.
Do you have any problems with other apps or is it only keyclone ? Can you run the 5 accounts (I will assume WoW) separate without using keyclone? And is it keyclone that is crashing or is it the WoW clients that crash?
Virus scanner up to date and ran a system scan lately ? how about a disk check ?