[SOLVED] gpu needs to be reseated at every use

Hi
I have bought a r9 280 vapor x
(bulky one, 2 x 8 pins)
It works but i have to reseat the gpu every time
when i haven't used my pc for a while
(usually less then 24 hours)

I don't have the issue with my previous
(also bulky) hd6970

any thoughts?

PSU : ocz 600 W
MOBO: P8Z77-V LX2
 
That's a big card, I realize the other one is big too but weight distribution could be different. I think when you use it, the combination of vibration from the fans and its size cause it to start becoming unseated. Over time it works itself out enough that you have to reseat it. Maybe if you could figure out a way to brace it in position it might fix this. The motherboard is an older one, the slot might not have the grip that it used to have.