I found they only way for them to go away is to restart zenoss.
Any ideas what could be causing the files to be deleted but still held open?
this actually happens often on a linux/unix box its something like the files are deleted in the "dir" or listing but the space is not returned to the filesystem until the process that is holding them open releases them.
There is supposedly some configuration file where you can adjust where these temp files are placed but I could not find it.