Readers of this list may recall my previous postings about problems
I've been having with UDMA in 2.4.x. E.g., see starting at
<http://groups.google.com/groups?hl=en&frame=right&th=5431687b5f68da06&seekm=fa.kpi9bmv.1c3al9f%40ifi.uio.no#link1>
or just search for "Kamens" in the lkml archives.
FYI, Alan Cox recently suggested that I try 2.4.18-pre3-ac2 to see if
it does any better, and indeed so far with that kernel I haven't
experienced any of the problems I reported previously.
jik