Why are my Firefox pwords not saving? They have all erased under Tools>Options>Security>Show Pwords.

I needed to find a pword for a site related to business. Went into find my pword under Options>Security and they were all gone. This was random as far as I know for no settings have been changed and the pwords have always been there in the past. I have done some stuff with System Mechanic, Spyware Blaster, and Hijack This recently but do not remember processing any tasks that would erase Firefox pwords. My signons2.txt file is accessible and I see them there, but have no idea how to get Firefox to recognize them. I have rebooted in Safe Mode to no avail. I have seen posts on the net about this with no solution. Your response is greatly appreciated.