Custom skin makes weapons invisible...
 

I'm working on an Italian Milizia Volontaria (Blackshirt) skin, and it's coming along nicely except for one thing.

The weapons disappear in first-person view. All the player sees is his own hands. The weapons fire okay, but the player doesn't hear anything (except for ricochets, if they're close enough). Other players can see and hear the weapons, but not the person using the skin.

Has anybody run into this problem? How can I fix it?