i have a 752n and my comp came with a cd-rom in the first slot and a cdwriter/dvdreader in the second slot so my first thought was that you had a smiliar setup since the model numbers were similar
upon doing some research on the hp site your burner is in fact a dvd+r/rw. please be sure you’re only using +r media. also, it says here the max write speeds for BOTH dvd+R and +RW are only 2.4x.
you should check to see what kind of burner you actually have (should be able to find out in the device manager. my brother’s more recent hp had a liteon burner) you shoudl check for firmware updates or whether you can crossflash the firmware to get better compatibility with media since if the max on your burner is 2.4x, you probably won’t be able to get any results even if you DO get the thing to recognize your media.
does the drive recognize cds? will it recognize a boot disk? if it doens’t recognise anything then it’s probably safe to say it’s a dead drive. you could try to get it replaced from hp and with any luck they’ll be out of that particular model and you’ll get a free upgrade since even if you do get your drive working, 2.4x is going to make video work a tedious process.