This is driving me nuts, and I'm not sure how to troubleshoot. I go out and do some portraits with remote flash and it works for about 20 minutes then the flash stops firing. I'm using an Olympus OMD E-M5, Pocketwizard Plus X triggers and a Yongnuo YN-560 II Speedlight Flash. The only real troubleshoot step I've taken, and I'm not sure if it's a good one or not, is pressing the test button on the trigger that's on the camera, and it fires the flash just fine, even when the camera won't do it. What are the best steps to take to find the weakest link? Thanks.