I'm having problems using my Plextor 48/24/48U (USB 2.0) external burner within CDA5 (WinXP). This drive works great and at high speeds with Dantz Retrospect (backup software) and EZCD Creator. Yesterday I burned a disc "successfully" (with red book compliance), at a whopping 4-6X average speed, that would not play in my cd player. My old drive (Plextor 8/2/20 SCSI) burned perfect discs at full speed that always played. I'm convinced CDA5 has USB 2.0 issues as I've browsed the forum and have noticed others with the same problems. My ASPI layer and drive's firmware is up to date. I'm also following SF's advice for solving buffer underruns:
http://www.sonicfoundry.com/support/SupportProduct.asp?FamilyID=16&Family=CD+Architect&TopicID=32&DetailID=653
http://www.sonicfoundry.com/support/SupportProduct.asp?FamilyID=16&Family=CD+Architect&TopicID=32&DetailID=653