I do not remember if I had changed it in XC_Bags by accident - most likely - or if it was in vanilla EE already ...
(It might have been one of the editor 'special tricks' that still edited the original when I hought I edited a copy made from it. ;-)

Anyway, the source of the bug seems to have been found: it was a wrong 'scale' in the root template of one of the metal helmets. The scale was changed from 1.0 to 1.5.

I do not remember who was the first one who found the bug, I think it was Smarmbot - thanks a lot Smarmbot, or it was the ever present Abraxas - thank Abraxas ;-)

The bug has been fixed some time ago in XC_Encounters and recently I found the motivation to fix it in both XC_Bags versions.

... still amazed how a wrong item scale can produce this effect ;-)