Thanks for all the great input.
I have a Mtn. Rack on my rear and have a wire basket bolted to that for my school books and work clothes. Then I cut off a 12" piece of broom handle and sawed grooves in it to line up with the vertical wires of the basket and mounted the handle horizontally on the back of the basket with tie wraps. Then I mounted my 3 blinkers to the broom handle. This puts the lights 3 wide and behind all the duds in my basket. If I put the lights on my seatpost, then my books and clothes would be in the way.
So that is where my lights are. Somehow, though I ride in all weather, I have not been in much rain in NYC in the last 6 months so I don't think it is water.
I called Planet Bike, and they say that they did have a bad batch come out of China last year. I probably got several lights with bad switches. They are gonna send me new lights after I mail them mine.
I am gonna try that nail polish trick though.