Maybe someone can point me in the right direction:

I've had the 755p for 18 mos. I have had no problems up until now and I love it. I am a basic user with no 3rd party apps installed.

I set up 2 mail accounts that auto sync every 15 mins--my personal POP acct and my business MS Outlook acct.

About a week ago the phone would completely geek out after syncing email. The new email notification ding would get stuck and I'd have to remove the battery to clear the noise.

I turned the sync for my personal acct off, but the phone still starts acting weird every time there's new email from the business acct. The sync process itself doesn't seem to cause the problem--only when I have new mail. Then the phone becomes suuuuper slow to respond, sometimes won't turn on or off. It may take 15 seconds to get the unlock notification up if it shows up at all.

I've done a hard reset but that didn't help. I do not have the latest firmware upgrade because I have a mac and you need a expansion card to install the upgrade and I don't have one.

Is there hope for this phone or is it just dying? Could it be the battery? I like the 755p and if it is dying, I'd get another, but since Sprint took it off their shelves just days ago I don't know what I'll do.

Any advice or suggestions is appreciated!