That sounds weird. About the only two things I can think of that might cause that are a problem with the Transpose parameter setting, or (probably less likely) maybe a problem with the Pitch Bend Wheel. If moving the Pitch Bend Wheel after the tones have shifted still allows you to bend the notes both upward and downward, then it probably isn't the Pitch Bend Wheel, since I was thinking that maybe the wheel is getting read as though you've got the notes bent all the way "down."
The Service Manual for the S08 is available from ElektroTanya:
http://elektrotanya.com/yamaha_s08.pdf/download.html. When you go to that page, look below the image of the manual's cover page and watch the line of text that says "This file is downloadable free of charge:
...processing..." and wait patiently for the underlined text to change to "
Get Manual"-- which will take anywhere from 15 to 30 seconds. Then click on the "Get Manual" link to download the PDF of the manual.
The Service Manual describes a "test program" that you can run to check out the S08. I don't know if that will help, but I guess it couldn't hurt! And if you're any good with electronics and electrical diagrams, maybe something in the Service Manual will help you figure out how to repair your S08 yourself?
PS-- I like your avatar-- Sinbad the Sailor as animated by Max Fleischer.
