Resolved: IRC Chat - PM bug
 

When recieving Private Messages from IRC chat, the account will show up multiple times in the user list. When clicking on the pm bubble for the second instance of the account, nothing will happen. When parting the channel they show up in, the accounts will remain in the list under no channels.

They will go away if you restart the client or connect to a server.

Ah, ok, misunderstood your post. If you are sent a PM and then you leave the channel before you read the PM, it will appear twice, and one of the names can't be clicked on.