I found the solution to the problem on this forum:
http://srforums.prosoundweb.com/index.php
The fix is simply to put waxed paper under the XLR boards. As I sat at the dining room table and tediously removed scr ...
A little further experimenting, and I no longer think it's the waxed paper under the boards. It's the fact that I moved the boards and re-seated the wire connectors that solved the problems.
