I also am very interested in downloading the drivers for my SX-PR804M. I actually bought it new and, a year of practice later, I'm finally ready to hook it up to my new Finale 2006 for some sequencing and, lo and behold, no CD in the plastic documentation bag!

I haven't found a lot of useful links at the manufacturer's site (I actually found one download link, but it went to a non-existant page!).

Incidentally, a low-fi solution may be had here: http://www.pasc.panasonic.com/epartr/PartslistChoice.asp?

Search by Part Number (notice radio button) and enter, for instance, PR804. It will cost you around 20 bucks and you'll have to wait for the shipping.