hrmmm... interesting. Have you tryed running it via nohup?
nohup ./client &
(could possibly also try piping to /dev/null)
That would pipe all output to a file called nohup.out. I don't know if it would work, but I would assume that if the output is being piped elsewhere (other than the video card) it may possibly run. I have it running like that on two machines fine. But they have video cards, so I don't know if it would work for you guys with diskless nodes. If it does work then you could just 'tail' the file to keep track of progress.
BTW I the Celeron 333 box has a video card, but no monitor connected and it works fine. I just SSH to it to start the client with nohup and I have had no problems with it. The nohup.out file shows that it's working just fine.