Failures burning with K3b

The system is openSuSE v10.3.

Yesterday I downloaded to iso images openSuSE v11.1, for 32-bit and 64-bit 
architectures; all yielded correct MD5 results in K3b. 

I first burned the 64-bit image, checking the "Verify" box. When the 
operation was over, there was an announcement that there was "nothing to 
verify".

I repeated the operation with the 32-bit image; at the end of the 
operation, the disk was ejected and there was a laughter sound to inform 
me of an error, so the verification failed.

I repeated this operation, without verification. At the end, K3b announced 
that it had been completed successfully. But both of these disks failed 
to boot the T21 laptop for which they were intended. When either of them 
is inserted into a running open SuSE system, the system seems to inspect 
them normally, but the CDROM drive does not appear in the "Disk 
information" list in Konqueror.

When I insert the 64-bit disk into the T21, it does boot the machine, and 
correctly announces that it cannot be used in that 32-bit machine. Either 
K3b has become corrupted or the drive has become defective; the drive 
reads normally. Short of substituting a new drive, is there a practical 
way to determine which?

I also tried to burn a DVD with some ordinary (non-image) files. This two 
resulted in the laughter. When I insert it into the drive in order to try 
to inspect it, the drive's activity LED never goes off, so I have no idea 
what is there, except that I have made another coaster.
-- 
Stan Goodman
Qiryat Tiv'on
Israel