I have the same problem .... Searching didn't come up with any resolution. I am still trying to troubleshoot but seem like the voltage output from the eggshape regulator is fluctuated around 12.6-12.8V. The AC adapter output about 12.5V. When I tried the eggshape and it happens everytime doesn't matter if I connect it to a constant or switched power source. Then I used the AC adapter and it did not happen. Maybe I will try the DC-AC-DC invertor.... and using the AC adaptor.... Will see if that help.