Did you turned the dial during boot to erase the memory of the WK8? Sounds like a memory error of some kind. You can try to do a hardware test, which is not difficult to do. I do not have my WK8 here with me, so I hope I got it right.

You go to General, then System Info, than you push F8 (Or the most right down F button, I think it is F8). This should put you in Hardware Test modus. You can check every button, the harddisk and your memory.

Hope it helps.