Pioneer DVR-105 1.30 to 1.33, can no longer write at 4x

I have the Cendyne retail boxed OEM Pioneer DVR-105 for almost one year now. Have burnt over 400 DVD-Rs at 4x without a single problem. My latest firmware burning at 4x is 1.30 official from Pioneer.

I update the firmware from 1.30 to official 1.33b last week. Ever since, I can not write to any media with 4x. NERO 6.0 with latest patch will recognize the media as 4x, and will try to burn the media at 4x, estimate minutes is 15min, but actually take 50+ min. The time is just not right. 50+ minutes for one disc is really only 1x buring. I tried using InstantCopy, same buring time for 4x media.

The media I used:
Princo 4x bulk
Maxwell 4x retail

With firmware 1.30, works fine at 4x. With firmware 1.33, I have already burnt around 5 copies of both media, looks like 4x, but only 1x burining speed.

So far, I tried:
Flash the DVR-105 back to 0.58 with DVRFlash, using 2xall 1.33, using RPC1 only 1.33, using official 1.33b. And, every time, I reflash the drive, I reboot the machine, uninstall the drive, reboot again. Still can no longer burn anything at 4x. The only other thing different from before, is that I plug the DVR-105 to the Promise Ultra TX2 ATA100 card instead of the mother board ATA133 socket directly, this should be the reason, right?

Any ideas? Please help.

answer =>

plug the DVR-105 to the

Promise Ultra TX2 ATA100 card instead of the mother board ATA133 socket directly, this should be the reason, right?

YES !!!