What tips can you offer for grilling "real" hamburgers on a gas grill?!

What tips can you offer for grilling "real" hamburgers on a gas grill?

For some reason I can never grill the perfect burger if I make them with fresh/handmade ground beef patties. I have no problem with frozen patties, steak, or chicken -- but for some reason fresh ground beef patties are a challenge.

I usually end up over cooking them, or they break-up and fall between the slats.

Thanks!

Use "Regular" ground beef, not lean or extra lean.
Handle the meat as little as possible while forming the patties.
Season patties with salt and pepper after they are formed.
Let stand until they reach room temperature (about 30 minutes).
Cook on high heat until medium (slightly pink middle) or medium well (barely brown middle, still juicy), turning only once.
Do not press down on the burgers or handle in any way other than turning them once while they are on the grill.

Bert