Searched and haven't found this issue:

I have a couple helmets. When I "try them on" (i.e. select the helmet from my inventory) I can see the helmet.
When I select "Equip", the helmet doesn't show on my character. It also doesn't show in-game.

Bug?

Samsung Galaxy S Captivate
Cyanogen Mod 7
Gingerbread 2.3.5