unfortuneatly thats not it. but thats what i thought at first.

The ful charge would only effect battery life, not the phone itself.

Do you have a really high res, or big file size pic as you background? This can slow down the phone some times.

i've had this phone for almost a year, and its been very sluggish the entire time. when i press menu it takes about 3-4 seconds for it to pop up. when i scroll through things such as contacts i can't go too fast. games on the phone suck cause the controls are so slow. when i first got the phone i didn't allow it to fully charge the first time so could that have caused it? also, is there any way to fix this and speed it up? maybe by totally reseting the phone?