Minsc was wearing this kick ass "Armor of the Hart". All of a sudden I notice it's gone. Completely gone. I didn't take it off. It just vanished.

Korgan left my group because my rep got to 19. I anticipated this so took away all his items before it happened, so I could give them to Keldorn. Korgan bailed me, and it turned out Keldorn came with his own armor. So I gave Korgan's armor to Minsc.

But any idea where Minsc's armor went? Does it expire? Can certain foes shatter the armor or steal it? Could Korgan have swiped it on his way out? I know for a fact I didn't take it off Minsc.

SPOILER
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The only occasions of permanently lost equipment to my knowledge are
the carrying character disintegrated or similar
and the loss of all equipment from your love when Bodhi kidnaps her/him.
even when a char is turned to stone the equipement will be given to the party and sometimes NPCs even leave their things with you as they run away.

There was also something said about monsters or enemies taking your equipment/armor or making it disappear. Hopefully someone else will know what I am talking about and give more info.

There was a bug with the Hakeashar (sp?) (I think) that meant that instead of just draining charged items, it could destroy all magical items.

And there is the Nishruu/Hakeashar bug, where Nishruus would eat up magic items (like the Girdle of Hill Giant Strenght for example) instead of only draining wands. Never happened to me with a suit of armor though.
If you consider it a bug (which I don't - it's just that Nishruus are more powerful with this feature) it is fixed with Baldurdash's Packs.

i know what u mean once my armour just dissapeared for no reason

You can drop your armour when frightened.

When Bodhi takes your lover, you will find all her (or his) items dropped in the graveyard, right where she was standing. Unfortunately that's probably under the stone arch. Go back and hunt around for them. Don't wait too many days though -- stuff disappears in Amn.

-- Nifft

try and download the patch, that might be it. hell, i got a new hard-drive, and now i have no problems.