NFS uses the following daemons (background process) to handle the work of making and maintaining connections:
portmap is always on port 111
nfsd is always on port 2049 (both TCP and UDP protocols)
The other ones get assigned port by portmapper unless a config file is set to make them use a static port. I won't be at my PCLinuxOS computer for another 6 hours, so it is hard for me to verify where that configuration is. On similar distributions (according to the internet), it is at /etc/sysconfig/nfs or /etc/sysconfig/nfs-common, but I can't give you real good directions right now. Ideally, these would all be on static ports and then you would allow these ports through your firewall.
For now, you could make sure portmapper is allowed and try again. Or perhaps someone with better information will come along.
It looks like we need to write an updated how-to for NFS