I've had some "run away" units, they just keep going past 100/100, had one at 210/100, I found if you shut down the program, go to the work directory and delete all files then re-start the program it will get rid of the confused packet.
Just don't delete any files called WURESULTS,
Gila, haven't heard of a problem like yours, have you tried the non GUI client? I've found it's more stable anyway.