I don't know what MID code the Bell discs will actually have...
Where are you purchasing these? links?
ProdiscS03 (4x DVD-R) usually burns very well on the 2500A.
However, there are some 'bulkpaq' discs in Europe with the MID code ProdiscS03 that a few people have reported problems with... Those discs may actually have a fake MID code or may just be very low grade Prodiscs.