Sorry Alfresco 2.1 is so old it is before my involvement with Alfresco.
You should be able to find the issue and corresponding code change within alfresco's SVN repository. Its probably not going to be easy though.
I thought I should also mention that NFS is deprecated in alfresco 5.0 and completely removed in the next version of alfresco. I removed it from the nightly build last week.