Pesterchum won't let me log into my account

[KingTreeGitHub]

I have pesterchum on Windows 7. I got it yesterday, and it was working just fine, but when I turned on my computer today and opened pesterchum, it asked m to sign in. So I chose my account using the drop down menu, selected my username, and tried to sign in. It showed up (with my username and chat color) for about two seconds before kicking me out and saying my username was already taken, please sign in again. I would use the drop down menu again and it kept doing the same thing. Help???

[arcaneAgilmente]

The default "close" behaviour of the program just minimizes it to the tray. (where your clock is) You probably have multiple instances of it running.