So I had an extended battery on my N900 for a few weeks, but ended up going back to the stock battery because the device was a bit too bulky. However since doing this the battery reader on the N900 has been way off. It will suddenly drop from half to red and sometimes it even goes backwards (from red back up to 25%) after letting it sit for a little bit. Any ideas why this may be and how I can fix it?

~Jeff