UPDATE !!!
had my first leak today.
See, I told you guys this thing was a POS!

J/K, of course. I've never had one leak, and this sounds more like an "ooze" than an outright leak. While I've never had a leak (although I've taken my share), one guy suggested that instead of pushing in a new tank and letting the atty spike punch the hole in the bottom, that instead you do it more "surgically" with an 18 gauge needle, commonly found on a juice-filling syringe. Never even found that necessary though.
Hey now, is this thread still alive?
So it seems.
@kaysesoze: Do you put your teeth on it and pull? I wasn't even aware the bottom of the cartridge came off!
Such a silly man.Just pop it off with a fingernail. Try it, you'll like it!
Chris, have you been using a syringe all this time? They come off and click back on just great, even after 50 times. Mine have never given me any trouble.
And hey, check out my edit at the bottom of post #55.