Chat window closing randomly on login
 

I've been noticing lately that my "chat 3" window will sometimes be closed out when I log in, forcing me to create a new one and re-assign filters to it. Any idea what would be causing this?

I've gotten this since the last patch, too. 'Locking' the windows hasn't helped, and for whatever reason the window's right-click menu will no longer let me set one window exclusively to 'Tells.'