I feel your pain. I also tried using those crappy Pur filters, with the same results - except that the lame handles kept breaking off, too.

When they came out, I bought a Miniworks and never looked back. I've never had any problems of any kind with them - nor have any of the half dozen or so I've given to friends and scout troops ever given them any problems. I particularly like how easily the ceramic element can be cleaned in the field. As far as weight, it does weigh a pound - my Pur filters were slightly lighter, but the need to carry at least one extra filter element made up the difference.

This was one of several pieces of gear that convinced me that MSR may not always be first with something, but when they do something, they do it right.