Does this happen in one area, or all over?
My (brand new) 8800 has really horrible coverage at my house so is constantly dropping and trying to pick up a signal. I'm sure that isn't helping the battery at all. I can only get about 36hrs of battery (and I might use 300 minutes a month).
As much as I LOVE 8800 design, it's darn near killin' me that it doesn't work at home
I plan to dump it as soon as Sprint releases their 8800 model.