Speedo trouble

Hey all, I'm new to tacoma world. I've wanted a tacoma for about 8 years now and finally got a clean '05 double cab prerunner. This forum is awesome and so far (with your guys's help) the mods I've done are setting up constant power to the cigarette lighters, disable the door ding, changed the LEDs on the gauge cluster to blue and currently am in the process of building a subwoofer box to go behind the seats. So here's the trouble. I just recently swapped the LEDs on the gauge cluster (a daunting task but worked out pretty well, or so I thought) and everything was fine for a day or so. Then I noticed that that while I was driving, the speedo would change it's base. For example it would read 10mph while sitting at a stop sign, read 60mph while doing 50mph. It's never constant though. Sometimes at a standstill it'll read 10, sometimes 25, sometime 32 and so on. If I turn the engine off, the needle will stay wherever the base decides it wants to. Only way I've found to reset it is to leave the truck for about an hour, lock the doors and then unlock them and open the driver door (doesn't reset if I open any other door) and that fix doesn't last long. Perhaps I bent the needle? Any help you guys can offer would be greatly appreciated.