If it's not a ROM problem then i don't know. However i've found this site and it looks like the expert Greg Donner knows what he's talking about so he may be able ot help you.
for an expert he seems a little weary from what i have read...
but fear not... i have signed up.... my request to join the experts is pending
we shall see ......
If i had a hammer, I would hammer in the morning, i would hammer in the evening, i would hammer all day