Weird problem with HP 8100!!

[drcreamx]

I just received an HP 8100 plus (4X2X24) burner. Burns onto cd-rw no trouble. However, when using cd-r disks (tried different brands) the burn seems to go OK (no errors) and the disk looks to have been written to. But when i try to read it, it is empty! happens with Nero and cdr-win under both win98 and xp.

seems funny to work only with cd-rw and not a regular cd-r.
any idea whats going on here?