I have had more luck reproducing this while in the SCUBA mission (ie: in the diving gear)

I have also noticed this issue, It should be expanded to include the fact that a pilots head will also clip through the roof when coupling FPV and either TrackIR or leaning. The act of leaning causes you to lean into the pillar and roof allowing you to see through it in an unintended way. I have not tested in multiplayer if the head glitches though from outside observers.

This seems true for the mini-guns on both sides while in First Person View. However from 3rd person view (exterior view) both guns function as expected.

I've found a video demonstrating this bug

http://www.youtube.com/watch?v=mnfIA0O4epA

Agreed, we need something, but I don't like the idea of ARMA adding a whole bunch of HUD Items, Something more minimalistic than Ghost Recon would be ideal even though something like Ghost Recons indicator was wonderful.

Very hard to aim the guns on this thing while using Track IR due to this issue.