I just checked the prices for B+W filters at Freestyle. Man oh man, they are out there. If you bought your filter new I'd march right down to the vendor and demand a warantee replacement. At that price you deserve it. If that is not an option for you I would try a few dots of Gorilla Glue around the circumference. You don't want to glue the glass to the mount, you just want to keep it from falling out. I suppose you want it to be able to expand and contract without strains in the glass.

I think Super Glue type glues, cyano-acrylics, are too watery. Other than the successful temporary gluing of a broken toenail at a soccer game my entire history with super glues has been one of disappointment.