Just started having this problem. I've used Memorex before with no issues...
I 12:56:20 ImgBurn Version 2.4.2.0 started!
I 12:56:20 Microsoft Windows Vista Home Premium Edition (6.0, Build 6001 : Service Pack 1)
I 12:56:20 Total Physical Memory: 1,963,844 KB - Available: 1,148,532 KB
I 12:56:20 Initialising SPTI...
I 12:56:20 Searching for SCSI / ATAPI devices...
I 12:56:20 Found 1 DVD