Patch 1.45 on clean install.
I'm in Act II, battlefields level 1.
One of the merchants is Keith, the white-haird wizard type, on the west side. In my game he is standing behind (north of) a building. I can walk behind the building and talk to him, as he can be seen through the building.
At some point yesterday, I came back to the battlefield and noticed that while Keith could be seen in the minimap as a dot, I couldn't find him any more on the main screen. However, if I spoke to another merchant while Keith should be in the screen area still, while I was in the conversation he would show up. As soon as I quit the conversation, he would either disappear or remain.
If he did remain, I couldn't click on him to initiate a conversation, even though his green circle subscript would highlight as the mouse would move over him.
In addition, if he did remain, he would disappear for good as soon as I moved away from his area. I could only make him reappear through the merchant conversation trick, but he would still be unusable.
I also noticed that when he was seen, he would be located a little lower than originally, which put him right inside the building.
I had to revert back to an earlier save, as I tried all to no avail (saving again, going in and out of battlefields, leaving area, etc...).
Anyone had this bug?