First off, I am a totaly new to AirSoft (see how many posts I've done

), so this may be a stupid question. I've searched Google and the forums, but couldn't find anyone who had this issue.
On Sunday I purchased a KJ GBB M9. I just got a chance to test it last night. When I fill the mag and shoot, the clip falls out (I now have a nice ding on the bottom of my clip after it hit the cement). After shooting a couple of times, the clip stays in normally.
I thought at first it may be beause I am left handed and that my fat finger would press upon the clip release button, but when I shoot with a gasless mag, it never falls out.
Am I filling it up too much (i.e. is the pressure too high to cause the clip to expel from the bottom?
Also I notice that after filling the mag, I hear a very quiet squeaky noise, as if there is a very slight leak. Is this normal (to expel excess pressure, etc), or is the mag likely pooched? I tried tightening the assembly, but it didn't help.
Any help for this n00b would be greatly appreciated.