Redhat 6.0 as delivered, with or without patches, advertises
via mountd that it supports NFS3, but it doesn't.  This
leads  to funny behaviour (see bug 2554) which is annoying
even though it can be worked around.

I suggest you add the (undocumented?) "--no-nfs-version 3"
option to the invocation of mountd in /etc/rc.d/init.d/nfs.
I propose this not only because it will avoid people like
me having to discover the problem and specify "vers=2" all
over the place, but even more because some people won't
come up with this solution and just basically it should
not be saying it can do nfs3 when it can't, that's what
the portmapper is for.