Queue becomed unassigned upon edit

Hi - I've seen this problem reported in other threads but have not seen a clear resolution.

I have two groups of technicians, each monitoring a different queue by way of role assignment. Email comes in and is assigned appropriately to the correct queue so the different groups of technicians can view only the requests for their queue.

A technician for the queue will "pickup" the work order making the technician assignement and each of the technicians for that queue can still view the request and everything is great.

The problem occurs when that request is edited. Let's say the technician who picked up the request edits it to assign the category - as soon as that edit is made, the queue becomes unassigned and the other technicians in the queue can no longer see it.

This is a major issue for us since it is important that the work order maintain the queue to process our role based permissions.

thanks -