error device not ready (incompatibile medium instelled)

[etay9012]

this is the log:

I 21:39:07 ImgBurn Version 2.5.8.0 started!

I 21:39:07 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 3)

I 21:39:07 Total Physical Memory: 2,086,316 KiB  -  Available: 1,375,268 KiB

I 21:39:07 Initialising SPTI...

I 21:39:07 Searching for SCSI / ATAPI devices...

I 21:39:08 -> Drive 1 - Info: Optiarc DVD RW AD-7200S 1.0B (E:) (ATA)

I 21:39:08 Found 1 DVD±RW/RAM!

 

i dont understand why i have this error 

[LIGHTNING UK!]

Your drive seems to be having a problem with the disc you've put in it.