I've been using TDK (700Mb CD-R80 blue tops) & Verbatim (700Mb 52X white tops) in My DUO & DUO-R with just a slight tweak to the pots. I tried a couple of other brands and had intermittent success (mainly skipping audio).
I do find burning at low speed seems to improve matters and if I use my trusty old Plextor SCSI burner I get better results.
I do find burning at low speed seems to improve matters and if I use my trusty old Plextor SCSI burner I get better results.

