Correct me if I'm wrong FP
The consensus might be that firmware 1.1 works best for making copies of Safedisc 2.90 and onwards, especially with DiscJuggler, and Alcohol 4.xx
Yes the drive is backwards flashable to fw 1.1
Firmware 1.0 is available, but I have never managed to flash it to my drive.
The only negative point about FW 1.1 is media compatibility.
Having said this, FW 1.1 works very well with Verbatim Datalife Plus CD-R, Moser Baer CD-R, Ritek JS CD-R media, and Mitsubishi US rewritable (24x), so you shouldn't have trouble finding blanks.
Hope this helps you.
Some firmware is available here (CDfreaks site)
Other firmware is available on Asus's site here (Asus site)
The Asus 5224a is the best drive on this planet for making Tages backups