I had similar trouble and I had to loosen the hatch pin connector thingies as they were too tight. You may wanna try and loosen both nuts on each side then play with the rods. If your climate has gotten colder this may be the problem as thengs have shrunk tight.

 

my problem seems the same, yet somehow, different. i can get in with the key just fine, but when i hit the button, i DO hear a wiir and then a slight pop, but i go back there and either only one side is unlocked or nothing at all. i remember both sides unlocking ONCE in over a year.

anyone have a pic of these pins and releases so we know what to tighten or loosen?