nfs-utils in Version "nfs-utils-1.0.10-1.fc6" fails for NFS in version 3. In my
mount option I use the flag "nfsvers=3", with nfs-util in version "1.0.9-8.fc6"
it worked like expected but with the new "1.0.10-1.fc6" I get the message:

NFS version 3 is not supported.

For example try it with 

mount -t nfs -o ro,nfsvers=3 nfs:/tmp/test /tmp/test

result is 

NFS version 3 is not supported.

but when I change "nfsvers" to NFS Version 2 like:

mount -t nfs -o ro,nfsvers=2 nfs:/home/tp1config /tmp/test

it mounts the directory.

I hope this is not the future... mount only for NFSv2 and NFSv4 :-)...