All I can say is I have not experienced this problem. However a poor ground or possibly low battery could produce the voltage differentional needed to trigger the IR. I noticed when my battery gets low, some strange things start to happen. Firing the IR will cause the DBU to light up, so if low voltage can do this, then I think it could cause the IR to shoot.

Try to notice when it starts happening. If it never happens on a fresh battery, I think the cure might be just a bigger battery to increase your usable run time.

Dan