I have had this same problem multiple times. unfortunately, my only way i had found was doing a factory reset. -_- I made sure all contacts were saved thru google, i wrote down the apps i cared about, and i made sure all pic messages were saved. and....once i reset it, I couldn't believe how fast my phone was. Personally, I HATE my Eris with a passion; battery life, speed, processor, touch screen, pocket calling, etc, etc. If the battery didn't blow and the processor was a bit quicker, prolly wouldn't mind.
Thank God i'm due for an Upgrade with Verizon...Now I'm hooked on google searching new verizon android phones coming out in the next 3-5 months....i think i can deal with this POS that long.