Buffer flushing! burning probs

[Mad Goldfish]

Ok i am currently running xp pro on a tbird 900
i have a yamaha cd burner with the latest firmware and i have installed the latest aspi drivers. my problem is this:

after installing svc pack 1 and all of the latest xp updates i can no longer burn on the fly anymore. This is using both the latest clone cd and the latest nero!

with nero it flushes the buffers at about the 40% mark and tells me buffer underrun error and cannot complete disc at once end of disk function (or words to that effect)

with clone cd it will merely lock up anywhere between 7 -31%

but with both programs i can still burn images from the hdd no probs

i just want burning on the fly to work so i can copy my music cds quickly and my computer illiterate mum can use it to copy easily.
any suggestions appreciated fellas, cheers