Merging quicktime components taking a LONG time

I'm using a 2.66 quad core Mac Pro (intel) with 12 GB of ram, running Leopard and FCS 3.0. I have set up a quick cluster with 3 instances (leaving 1 core available for miscellaneous processing tasks) and am trying to convert XDCAM EX 720p60 clips to ProRes 422 for editing. The quick cluster seems to be working fine; the files get rendered fast enough. The problem I am running into is at the end of the encode compressor takes forever "merging distributed quicktime components". It is taking so long that I'm guessing it would be faster to simply use the local machine instead of distributed processing. If so, this is very disappointing.

Am i doing something wrong here? Is there any way to speed this up so that I can actually take advantage of having multiple cores? I recently obtained an 8 core machine (which I haven't tried using yet), and likewise I'd very much like to be able to use distributed processing on that machine as well. Thanks!

Dave