Samsung LE37R87BD

[sparkman001]

I know there are a lot of faults listed re this model Sammy but I havent seen this one before. The set works with a good picture, then about half an hour later the contrast will begin to advance by itself to 100%. You can reduce this in the menu, but again after a short while, it will increase once again.
Now, my instincts tell me faulty EEPROM, but before I embark on a wild goose chase, has anyone had this or a similar fault before.
Many thanks
Bill