Clicking on the x doesn't work, nor does right-clicking taskbar and close. It simply freezes.
Only way I can close it is by terminating the application through task manager manually.
I've had this problem for as long as I can remember (since at least .81, and it persists after uninstalling it, deleting every folder associated with it and reinstalling.
Didn't really get around to mentioning it before, as I had only updated Spring recently to .86 (was previously using .82)

Windows Vista Home Premium SP2 (all current updates applied)
Intel Core 2 Duo E4500
Fujitsu Siemens G31T motherboard
2GB DDR2 333MHz
Nvidia Geforce 8800GT
1 500gb and 1 1000gb HDD (can't remember the brand, but I figure it's hardly important)
Creative X-Fi
All drivers up-to-date

If you really do mean SpringLobby those version numbers are excessively old. Update to 0.141 and follow viewtopic.php?f=64&t=25464

No, that's the version of Spring itself i'm currently using. Springlobby is at 0.141
It's been doing since since at least double digit Springlobby versions, though.

Or try a different lobby. TASclient works great for me.