My first thought was to try upgrading the firmware, but I can only find the firmware for the internal version of your drive on HP's site (which I do not recommend trying to use--it sounds like there were several different manufacturers HP used for the drives of this model number, and you've got to know the exact one for them to work).

Of course, from the threads I've seen from trying to hunt down a firmware upgrade for your drive, it sounds like even those with the same burner (and problem) who did find firmware upgrades and installed them didn't have any luck. I hope this isn't the case for you, but it sounds like you might be screwed because HP's support is pretty much non-existent.