2.6.9-rc1-mm1 contains patches that can cause data loss. See this thread http://lkml.org/lkml/2004/8/27/59, which contains a patch to correct the problem.
my personal rule for kernels:
never expect a rcX-yyZ to work!!!!
rcX means: we need testers for vanilla - made under time-pressure
yyZ means: it's another tree than vanilla
this together can cause difficulties
thanx for letting us know - i forwarded it to kerneltrap
The impossible missions are the only ones which succeed.