Finaly I find some time to investigate more into this situation of lock volume acces - multiple handle open...
This is the log that ImgBurn produced to that investigate session...
I 20:51:10 ImgBurn Version 2.4.2.0 started!I 20:51:10 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 3) I 20:51:10 Total Physical Memory: 2.095.532 KB - Available: 956.048 KB I 20:51:10 Initialising SPTI... I 20:51:10 Searching for SCSI / ATAPI devices... I 20:51:10 Found 1 DVD-ROM, 1 DVD