I have 2 SH-W162L DVD±R/RW drive-a under XPpro Sp2
And I have an strange isue: my drives can't recognize DVD RW discs! I tried difrent brands (Philips DVD+RW, TDK DVD+RW and DVD-RW & Sony DVD-RW) but I don't have problems burning regular DVD-/+R and CD-R & CD-RW discs! And yeah I have upgraded firmware to latest version (TS03)!
I even reinstaled XP! No problems with older burner (RIP now)!
Any ideas?

Disconnect the first drive, and try it. Disconnect the second drive but connect back the first drive. What are your results?

Make sure the drives are set as master/slave properly on the secondary IDE.

Tried method sugested... no change, except one drive (seting: master/slave)(curently slave) displayed on statup (in bios sc) ''drive bla-bla not ATAPI compatible'' but with bouth connected no problems (stil not reading DVD-RW-s in any combination)... thanks for trying...

Set each one as master and try them individually.

Ensure you are using an 80 pin ide cable, and that the pin 1 stripe is oriented the right way.

If you have another PC or a friends PC etc. Try the drive with them.