Well, if it is only the -12V line, then dont worry..it is not used anymore. As for vcore, if the system is stable, then it should be ok. I bump up the vcore by 0.05v to run my 2500+ at 3000+ and it is perfectly stable. So if your system is not stable, try that. If it works, then you may be able to use your PSU a bit longer
-Always put the blame on you first, then on the hardware !!!