The overclock on GPUs bringing issues is something that the developer needs to address. You don't seem to be the only one with that issue.
No it isn't. If overclocks are causing crashes or glitches it is because those overclocks are not stable. This is a mistake a lot of overclockers make: an overclock might seem stable everywhere else, but if it's not stable on absolutely everything then it's not stable, period.
Hmm...I'm not too sure what to make of this then..return the card? To clarify, I haven't overclocked the card past the factory OC. I will experiment with taking 105Mhz off the clock (most I can downclock) this evening and report whether the issue persists.