Hello people,

I found the source of my problems today, while reading the
man pages for pciide and wd.  It looks like in the generic
kernel, ide flags are set to 0x0000 meaning 'use whatever
DMA settings the controller supports'.  That is a terrible
mistake when you have a crappy pciide controller (in my case).

Setting the flags to 0x0f9c (took me a while to figure this out!)
as in PIO mode 4, DMA mode 1, disable UltraDMA fixes the timeout
problems.  Now I can pull the plug while the server is running
and fsck will fix the filesystem after reboot without any
timeouts.

Thanks for everyone's help!