Hi krayzkrok!
What chimera99 is trying to say

is: There actually ARE (it took me very long to find out, that's why I mention this here) chests, that are locked, but not traped. The interface looks like the doors, with the tumblers, and that's where the manual is pointing to. Trapped chests ARE opened... well, nobody said that spells care much about daggers, right? Just thought I'd mention this...
Never forget your towel, cheers
Philipp