I have my own transponder that I bring with me when I travel in IL. I just received a notice of 2 toll violations from Feb 2009. It seems my transponder didn't pick up the charge at the same toll booth in both directions. All the other toll booths worked fine and were charged to my transponder.

I go to the trouble of calling i-pass and registering my rental car plate with them every time I rent a car, so if the transponder doesn't work, the charge should be put against my account instead of Avis. This seems to be a waste of time.

Does anyone have any advice on how to make sure I don't get these toll violations?