I guess isn't happening to everyone and the other person (Relandi I think) who mentioned in IRC that he experienced it said it didn't happen all the time. But I do have fraps evidence that I can post if necessary. But it's pretty simple.
I dropped one of my character's bag on the ground so I could grab some things from it for my main. However when I open the bag it keeps closing itself a few seconds later (time seems random).
The bag in question can be found at Z190, 959.52, 1820.60 (unless someone takes it). Maybe someone else can check if it happens to them as well.
I did notice that one of the changes was to fix the bug of being able to open a bag on the ground and have it remain open no matter where you went. Bags close immediately now when you move. So maybe this bug is related to that change.