Sonnet Tempo ATA133 slow

I have a Sonnet Tempo ATA133 that I was using under 10.4 to run my Pioneer DVR-110D drive at a reasonable speed. Since installing Leopard (which took four hours), I've noticed strange things with the DVD player. I finally discovered after an excruciating long reinstall of GarageBand and three of the Jam Packs that with the DVD player, I had the kernel_task take up 88% of the CPU. Running the install from the CD player caused the kernel_task to take on 56% of the CPU.

I moved both drives off the Sonnet Tempo ATA133 to the internal connector (either the ATA66) and everything seemed to work better, installs were faster and no more kernel_task hogging the system.

The issue still remains that the ATA 66 doesn't drive the DVD drive at top speed (which is why I originally purchaed the ATA 133). Both my internal 133 and 100 connectors are driving disks, so moving the DVD writer to one of those connections is combersome and not ideal for me.

Does anyone know of a patch or a fix for the Sonnet Tempo ATA133? or is there another PCI card that will work with Leopard? Haven't seen much on the forum in the way working 3rd party hardware for my not-so-old Mac? (And I'm not quite ready to upgrade to a new box yet, but thanks for the thought.)