With at least one toon I play on a PW, I notice that the slots on his quickbar get mangled between logins. The case that I am noticing is one where two-item slots are affected, though I don't know if the issue is limited to that or not.
In this case, I have the F3 slot set for a short sword and a shield and the F6 slot set for a sling and a shield (the same shield). Then I log out and log back in. Both of those slots on the quickbar are set for a magic bag (both set to open the same one). I have no idea why that would be. I have never deliberately set a quickbar slot to open a magic bag. And, FWIW, it's not even a magic bag containing either of the items I am trying to equip.
A detail that seems significant is that the shield is in a magic bag (though not in the one that gets quickslotted). If I take the shield out of the bag and set up the slots, they remain correct when I relog. If I put the shield back in a bag, the slots are corrupted. It doesn't seem to matter which magic bag I put the shield in.
I also noticed that the magic bag that gets slotted seems to be the same one all the time. So, I dropped that bag on the ground, set up the slots, and then relogged. (The shield was still in another bag in the PC's inventory.) This time, the shield was lost from both slots, but the weapons remained in it.
After all this time, this is probably a known issue related to two-item slots where one item is in a bag, but I didn't see anything when I googled for it. Does anyone know what's going on here? Is there a fix for this? I mean, aside from the non-fix of not putting the item in a bag. (For many of my toons, it's not an issue since I don't keep their shields in bags. But, for dexing toons, some of them are always near encumbrance, so a bag is useful.)