I2500k minor overclock too much for PC?

Hello

So I have OCed my system from 3.3 to 4.2 and everything seems to be running fine, but there has been an issue with my PC since then. I had my rig running solid for about 2-3 months until one day it just turned off and wouldn't come back on at all. So I sent it in for repairs for free through warranty and found out that it was a faulty PSU and the PSU took out my GFX card with it. Both were replaced and I have had it back for about a month. All same settings and everything is running fine until today when I booted up the computer shutdown and restarted during the very beginning boot process. Everything booted perfect after that and I'm on it right now with no apparent issues at all. I have checked temps and everything looks really good. I called tech support and they said that sometimes intel chips will do that and its perfectly fine. So, can OCing to 4.2 by simply changing the multiplier to 42 be an issue for my setup to the point where I should set it back to defaults? I really didn't think it would since my rig should be able to handle such a simply OC and my temps look great and I've never seen BSOD or any other boot issues. Hope its not another bad PSU....

i5 2500k
ASUS P67 Sabertooth
8gb DDR3 1600
Asetek 550LC Liquid Cooling w/ Dual Enermax fans (push pull)
EVGA GTX 560 Ti (Factory OCed to 900mhz)
Corsair 850AX