Mixdown causes insta-crash

Hello again,

I have Blender 2.45 on Windows XP, updated, with a quad-core processor and plenty of RAM, so I don’t think it’s my machine, but -

Every time I try to mix down an audio track, Blender instantly crashes with the message that it has encountered an error, etc etc etc.

I tried:

loading movie + audio (HD)

just adding audio, from the combined file of images and audio.

In both cases, the crash was immediate.

I followed the instructions I found here:

http://wiki.blender.org/index.php/Manual/Audio_Sequences

Argh!

Any clues welcomed.

Thanks