Is my PSU the limit of my OC'ing? 12v rail is pretty darn low =)!

My 12v rail dips to about 11.61v and sometimes even 11.53v when oc'ing, and then the system locks... is my PSU the limit of my OC'ing? Temperatures are fine during this, and no programs error, the system just locks once I load it with prime95 and the rails start to drop. Would low rails cause the system to reboot, or can it cause the system to lock like I'm experiencing? I'm thinking of ordering an Antec TrueControl 550w PSU from newegg (was originally thinking of a Fortron 530w, but I want the adjustable rails) as it has been recommended a lot on these forums. Would this solve my lock-up problem and let me overclock to my system's potential, or is something else the cause of this? Thanks!

It is most likely the PSU. The TrueControl 550 is one of the best PSUs out there (beating even the PC Power & Cooling Turbo Cool 510 in the latest Tom's Hardware PSU roundup). If that doesn't solve your problems, then it's definately something else.