Joel, I encountered the exact same problem for the exact same reason. The answers you have been given are the correct ones and the ones I implemented. Raising the UR91 to head height behind a backdrop solved 90% of the problems. It appears the human body does create an obstacle to the radio waves the UR91 uses. Purchasing a UR93, two UT6's and a UT602 solved 100% of the problem. I now operate with 7 or 8 operators in a 14X20 room with both my UR91 and UR93 functioning and have eliminated all of the problems.
