Do you recall ever seeing the info that polo posted above ? As he said there is no MEDIA ID or write speeds shown in your log.
Maybe the drive has broken ? I see from the rpc1.org site (firmware updates) that there is no update available, I don't know anything about that drive but given that you have had it at least 2 years it may have just retired itself.
The firmware page is here if you wanted to check:
http://forum.rpc1.org/dl_result.php?kaj=1&isces