I noted that I had qdeled quite a few jobs from the cluster two days ago. Well, the ILC user I contacted through the CIC portal responded, apologised and thanked me for the suggestion of adding a timeout to lcg-cp. However, the biomed user (110 jobs) didn't answer. And in fact they continued to submit jobs onto the cluster and I was forced to clear out another 42 jobs this afternoon. So, if nice doesn't work, try nasty - I have ticketed them and will ban them from the cluster if I don't hear back within 24 hours.