It might have something to do with joining a game the moment it ends. My client tends to spaz when this happens, bugging out the queue option for a few minutes and then reverting to normal.
Not sure, but I assume the game I spectate have finished and I have afk for a while since it finish, when I click back it just brings me to this. EDIT: Nope, tried a few times, cannot reproduce it, sorry
This happened too me a few times a couple months ago i posted a screen shot and everything. What i did to correct it though was either closed the client or kept hitting ranked que and then back until it showed my bg list. If that doesn't work i have a couple other things i tried that might work also.
some time ago the game acted "just a little strange" (didn't post them earlier do to the horrible cropping)
Try cleaning out your cookies, and or restarting your computer. Yours looks too be a serious memory leak my friend that played pox for a while had a similar issue except every unit was appearing as a hulked up bunny.