Korg Poly800/EX800 Users

Hi ---

I like my Poly 800, but something strange is going on. Only about the 
first 21 voices are still there. The rest have disappeared.

Sometime ago, I had the unit checked by a tech and he assured me that 
the battery was just fine, and did not need to be replaced. I found 
this somewhat hard to believe, since I purchased the unit new in 1986 
(!)

I also had him upload all the factory voices back on, and shortly after 
getting it back from him, is when I lost most of the factory presets.

Ideas, anyone??

Thanks, in advance,

 - Dana Countryman