I don't know what your disk quota is exactly (Francis or perhaps your PI would know). But you can tell how much disk space the experiment is using in Windows by right-clicking on the experiment directory, and selecting Properties. It will start counting and eventually should show you the amount of disk space used.
I don't know that this is the issue, it's just one thing to check. Another thing is to look through the bputil logs in question (located in /data/users/LOGIN/bputil/logs) to see if there are any funny things in there.
I have only interacted with the interface you created for the newest version of bputil. I have no idea how to do anything in UNIX. I'm willing to learn if you want to point me to a UNIX tutorial or explain how to open this script. ??