Dale,
You didn't clean the surfaces or the surface that you were adhering to wasn't compatible with the sealant. Also be sure that it was indeed Dow 795. They have many formulations, each one with a specialty and a few with weaknesses. And silicones are in no way equal.
Ron,
Dow 795 is the proper silicone for the purpose. A few years back they reformulated it so now it's also a structural silicone, similar to 995 but more weather/UV resistant. Be sure to mask off the places that you don't want the silicone to go. I've given instructions on this and other sites a few times so you can search for them. And be sure to tool your joint. If the joint isn't tooled, it isn't warrantied. In order to have a watertight joint, it must be tooled. A wet finger, plastic spoon works fine. Home Depot sells a tooling spray that works really well. Costs about 4 bucks. I adhered my 60" X 10" portlights to my cabin with structural glazing tape, then sealed with DOW 995, white. A squirt of spray and spoon and the joint looks like an extruded gasket. Be sure to mask.
Oh, I'm a monumental skylight designer.
Don