R7 260X stuck at 300MHz core clock?

[Dare]

I recently bought an R7 260X from another member here for gaming and a little bit of scrypt mining (on my own altcoin, which is still CPU-mineable, so I'm not concerned about difficulty). However, despite purging my old Nvidia drivers, installing the latest "stable" version (14.4) of the AMD drivers, and fiddling with numerous settings, the card refuses to leave its 2D graphics idle clock speed of 300MHz at PCI-E x1.1 under load reported by GPU-Z. It's supposed to run at 1.1GHz PCI-E 2.0 (since my motherboard doesn't support 3.0), but nothing I've done has helped.

Has anyone else experienced this problem? If so, what was the solution? Google turned up a lot of fixes, but none of them worked for me.

[Dare]

Necropost just in case anyone else finds this looking for a solution: I RMA'd the card with XFX and got a working one, it took about a month but they responded quickly and the RMA process was pretty easy. They weren't able to tell me what the problem was specifically, but they did say that it was a hardware error that they couldn't fix so I got a new card out of it. The new card ran at 1075MHz instead of 1100MHz like it was supposed to, but it overclocked with zero trouble so I suspect they just sent me the card without applying the factory overclock to it. The new card also came with another Radeon Rewards code, which was nice.