Dvd+rw ok but dvd+r wont burn and lock system

Hello. Maybe you can help me. I’ve used my HP 200i drive for 1 year on my P-III , OS Millenium with no problems at all. Now I’ve another pc P-IV with XP Prof installed and When I use Nero (same version 5.5.9)my record stops and lock my OS and i have to reboot my machine. This happens only with DVD +R media (I’ve used HP and swisstec dvd’s+r). It works fine with DVD +RW.
I’ve uninstalled DLA and tried with different media , but the problem remains.
Anyone with same problem? Thanks.