As I wrote I tried 2 diff dvd's and normaly I dont have any problems with either.
Log for my imgburn:
I 16:08:11 ImgBurn Version 1.3.0.0 started!
I 16:08:11 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 2)
I 16:08:11 Initialising SPTI...
I 16:08:11 Searching for SCSI / ATAPI devices...
I 16:08:11 Found 1 DVD-ROM and 1 DVD-ROM/CD-RW!