Sorry necro such an old post, but I've found it hard to find this problem addressed. The glitch has nothing to do with your cache files, it's a bug involving where you are located when your bills arrive in your mailbox. When received notification that my bills has arrived when I was on a retail lot (I own a retail store) my bills where about 5x higher than they should've been and when I received notification while on vacation they exploded to over 10x. But, when I remember to be home when the mail arrived (every Monday morning) they were what they should be. This has solved the problem for me and I hope you find it useful.