TM Magazine leak

[Zyre]

3 quick questions...

I've got a TM Magazine that I was told should work in my KJ M9. It seems to shoot alot of gas out of the ejector port as if the top seal wasnt making a good..well...seal inside the gun. It also dosnt fully cycle properly, it just brings the hammer to half-cock and sometimes will load another BB. If I push up on the bottom of the mag it seems to work fine. Any thoughts on what I can do?

Also when I was reloading my KJ magazine I lost my grip on the end of the piece that sits ontop of the spring. The 3 bbs that were loaded went shooting to the top of the magazine and broke off one of the feed lips. I managed to find the broken plastic piece. It didnt shatter, so it looks like I can just glue it back on. Can anyone recommend a glue I can use?

EDIT: I did some more searching around, and came upon this thread: http://www.airsoftcanada.com/showthread.php?t=7932 saying that there isnt enough pressure to close the valve again...I'm trying to use duster in this gun, and I think it was meant for green gas, so could this be the reason? It could just be coincidence that it worked "ok" (but only ok) when I was pressing up on the mag. Maybe my hand was warming it or something.