Video of the bug: http://youtu.be/PEi1GliqQmU
Explanation: When they reload type CLIP is used, guns have a clip size of 0 and cannot fire.
Edit: Using build #353

You have to set the size of the clip in the gun config, clipSize=[clip size]

Ok, thanks. I did notice that when firing the total ammo count increases by 1 until the clip is empty, at which point the ammo count resets to the correct number.

Edit: Additionally, when you run out a clips the total ammo becomes negative and you can fire infinitely.