hello, my NBA fastbreak keeps resetting the settings/bookeeping upon turning the machine off. when i turn the machine on, the first message is "bookeeping and factory settings have been reset". i replaced the batteries, but it still seems to be doing it. it is happening about 50% of the time....every once in a while it boots with no error message, but it seems to be happening more often. this started a week ago. Any advice would be helpful. this is a Bally/Williams machine from 1997 and there is no corrosion around the batteries.