WE 1911 MEU Difficulties

[TLaw]

WE 1911 MEU - Three magazines: 2 meu mags, 1 non-meu. The non-meu mag has a broken top rendering it useless. 1 of the meu mags leaks (I was sent another to replace it)
- With the MEU mags I was only able to get 2 shots off before having to refill
- With the Non-MEU mags I was able to get 30 shots off.
- To make the Non-MEU use able I replaced the top with the top from one of the MEU mags.
- Now with all three of the mags I can only get two shots before having to refill, I put the original parts back onto the Non-MEU to test it and I still only get 2 shots, I have tested both to make sure I didn't mistake the pieces.
What can the problem be?
NOTE: This gun has had no prior use b/c when it was first sent the 1st magazine leaked and I had to send it back, due to failure by GI I was sent the same gun and leaking magazine (I'm positive), and I had to get an adapter which only arrived recently.

[Dominum]

Have you checked to make sure that when the gas release on the mags are pressed they fully open the valve?