How to get cd transfer speed back?

[Rhialto <rhialto%falu.nl@localhost>]

Recently my kernel told me this (among other things):

cd0: transfer error, downgrading to Ultra-DMA mode 1
cd0(viaide1:0:0): using PIO mode 4, Ultra-DMA mode 1 (using DMA)
cd0: transfer error, downgrading to PIO mode 4
cd0(viaide1:0:0): using PIO mode 4

I think this was due to my trying out the "digital" command of cdplay,
which my dvd drive didn't like at all.

The problem is now that burning dvds is now incredibly slow and uses
50-90% CPU time.

How do I get to my original transfer speed back? I tried atactl but that
failed with errors like "inapproptiate ioctl for device".

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert    -- You author it, and I'll reader it.
\X/ rhialto/at/xs4all.nl      -- Cetero censeo "authored" delendum esse.