Can't use anything in my inventory

[ryant16 0]

I haven't been able to use anything in my inventory for ages. I click on say a bandage, and the bit that pops up that you click, goes behind the inventory menu. Has anyone got a fix for this, it's so frustrating. my game is updated properly. I thought it might be because i used arma 2 free and OA. Anyway, can anyone help?

Screenshot from a while ago:

http://steamcommunit...9882?tab=public