I don't normally reply to myself, but there have been developments I can't explain. I popped in a previously mastered DVD+RW, ran the speed test and it started at just a little more than 3x and ended at 8x.
On a lark, I tried the speed test on the +R disc I first wrote about. This time however, it started at 3x and ended at 8x. It seemed the +RW test nudged the drive out of slow mode and it now reads at full speed. I'm at a loss to explain this. If you want to take a crack at it, please do. I just hope the drive won't default back to slow speed every time it's shut down.
As a side note, how long should I expect media recognition to take when I put a disc into the drive. CD Speed tells me a previously written +R discs takes 7 seconds to recognise. Isn't that a but on the slow side?