It looks to me like the computation of the total of a character's inventory is run when something is added to or removed from the inventory and not rechecked "on the fly".
When you make a temple contribution, however it is that the goods disappear from inside the box this is apparently not being seen by NWN as a change to inventory. After the temple contribution, the weight of the player inventory still includes the things given away - the weight seems to stay there until the next time the character adds or removes something from his inventory.
Is there maybe some simple thing that should be done at the end of the "gift accepting" script which would cause the inventory to be reweighed?
I just had a thought...Sen has been making anonymous donations lately...thus he does not receive a receipt, thus there is not an item (the receipt) added to his inventory at the end of the process. This problem may be restricted to the case of giving an anonymous donation and therefore not receiving a receipt.
Sen has an RP reason for anonymous donations right now but he generally wouldn't mind the receipts...except ten of em still makes a pound and he makes lots of donations,it'll probably be a problem for him when he has ten pounds of receipts in his pack...
If I'm right about this, the solution could be easy - anonymous donations get a 0 weight receipt that says "received from anonymous" on it...because sorry, temple auditors require that a receipt is given but they do not have to show the donor's name on it...receipt of the receipt should force the recalculation of the weight. The virtuous anonymous donor can throw it in the trash later.