Product: DayZ Experimental v 1.08.153164 - no mods
Description: As player's weight changes over time by items going in and out of his inventory, the stamina does not decrease and increase correctly - over time stamina remains low even when player carries very little overall weight. One example when this was observed was when I had some backpack and I was using it for some time (~hours in single session), I had it half-full with some items, then I found exactly the same backpack with exactly the same condition - I moved my item to this found backpack and my stamina restored significant bit. It was same backpack, same items, no wetness, no known modifiers to it overall weight. This same was observed when changing trousers inventory or jackets.
This can be certain specific item(s) causing this (I did not identify which one) or there is weight->stamina calculation error that accumulates over time.
Giving this "Major" severity as this seriously impacts gameplay - with stamina calculated wrongly too low (or high) for your weight player has serious disadvantage (or advantage if stamina results high)