Does anyone using GO PRO HD having issues with suction cup?
 

When I mount mine, the bottom part of suction cup doesn't seem to hold well.

I can't seem to understand how to mount this thing preperly:ughdance:

never had an issue with the suction cup on mine

Make sure the suction cup and mounting surface are clean and dry, and ensure that you press the button down all the way and then lock the latch.

Haven't had any problems with it mounting it to the Z during canyon runs, or on a kart while I smoked the So Cal crew, so like mustang said, just make sure the surface is clean, and when you put it on, press the button all the way down and then lock it. Wiggle it afterwards and if there's any movement, re-do it.

Can't speak directly to the Go Pro, but I always get suction cups slighty damp before mounting. They stick a lot better that way.