As part of my warranty work I had them modify the overflow drain tube on the freash water tank. When they were doing this, they noticed the area around the tank was very wet. Lo and behold, I had a leak in the tank. Apparently, in order to get the silverleaf sensor in the tank, they heat up the plastic and bury the sensor in the plastic, but apparently mine got overheated, resulting in a weak plastic spot that gave way and caused a leak. This procedure certainly does not sound like an exact science
I assumed that the reason my fresh tank was showing lower water after travel was the overflow/siphoning effect that had been discussed here on the forum.
In any event, I'm REALLY glad I asked them to fix that drain tube or this problem would have gone on undetected for quite some time..