I may be wrong, but my understanding is that a problem with the male causes infertile eggs and a problem with the female causes slugs. There are a ton of different things that can cause slugs, but stress or incorrect thermal gradient are the ones that come to mind.
I feel your pain though. I had 2 females slug out after a move. They had been building over the move and ovulated at the new house. The next clutch was from a female who developed follicles after the move. 6 perfect eggs.