I have had my cover come open once while on the road and that was because the battery tender harness was pushing on it. I have not had an issue other then that. Sure mine does not clip tight, but no issue yet.
My 08 had the same problem. I was told they were replaced and so I bought a front and rear one and have not had a problem since. The new ones have both the female clip that goes on the frame and the door male piece. They both have a screw to hold them in place. Sorry, I didnt keep the wrapping to provide the part numbers.
As other members of the forum have done, I drilled a small hole thru the clip so I could drop a wire tie thru the hole. I didn't tie it off, just dropped it thru the hole. No problems whatsoever.
I had an 05 that would pop open once in a while, I also drilled holes in the tabs and zip tied. The thing I hated most was before the fix I was always looking down to see if it was hanging, took away from the riding experience some.