Two recurring problems with distributed processing in Compressor

I'm trying to use a 3-machine cluster in Compressor, but I'm getting two recurring problems.

The transcodes always start OK, but there'll always be a problem eventually. One of them is that at some random point during the transcode, I'll get a failure due to a sudden inability of one of the machines to access the shared storage via NFS.

The other is that one specific machine (always the same one) will fail with a QuickTime error 60.

Is the first problem likely to be something that the IT guys at my company need to investigate? It's a particular bummer because the machine that keeps bombing out with the NFS error is a 16-core Mac Pro (the other two machines in the cluster are 4-core iMacs). As for the second, I don't know what error 60 is, but as it keeps on happening on the same machine, I guess a reinstall of QuickTime might be in order?