Taking Ldub's advice one step further... if you find that after adjusting the rubber stops the hood sits too high to the fenders, you would then need to adjust the hood latch.

There are 3 bolts to loosen for the latch. Make sure to keep it centered, but lower it just a bit and this will give you the extra pressure needed to pop the hood up... there will be some fine tuning involved with a few trips back and forth to the release lever inside.

Also, clean the latch well to get all the grime off so the mechanism works smooth, then spray some lube on it. Work the latch a few times without shutting the hood down. (use a screwdriver or 1/4" extension to latch by hand) Doing this will also tell you if the latch is releasing on it's own... if you don't get a good snapping action of the latch releasing, then it just may be time to replace the cable.