In om (Jerry Greenberg):
You are much safer to use grounded extension cords. This is the best,
even though your lights themselves do not use the true ground from the
outlit.

I would suggest to clean off all the cords, so that they are dry.
This means unstringing them and bringing them in to clean and dry out.
After they are dry, you can put them back together. Wrap the joints
with several layers of plastic bags, like the ones that you get with
your shopping order. On the edges, wrap a few turns of electrical
tape to seal them, so moisture cannot get in where the joints are.

This way of insulating the connecton points, will prevent water from
getting in. You should not have any ground fault problems this way.

Jerry Greenberg
http://www.zoom-one.com



Eliminating the ground leading out of a GFCI outlet will not "fix" the
problem. The GFCI detects a diversion in current from hot -- neutral to
hot -- ground. The ground lead is superficial past the GFCI for the
purposes of tripping it.