Does all the other speeds in your burning software still show up but if you pick 24 it still burns at 4 or does it just show X4 now and no other speed. You could go to your Device Manager under the drive and make sure its running in UDMA mode instead of PIO.
I've got a fairly new sony burner that used to burn cds at x24, but it only burns at x4 now nomatter what I've tried. Any ideas?
Control Panel-System-Hardware-Device Manager-IDE/ATA controllers
what blank cdr's are you using? have you changed brands?
Ok, the secondary drive was set to PIO. I'll see if that fixed it.