Nokia E51 won't disconnect after WLAN scanning

I was desperately seeking for a solution to this problem: whenever I start WLAN scanning, as soon as I turn it off, the WLAN scanning pops up asking to connect to a network. No matter what I chose (either to connect to a network, or the red button on keyboard), WLAN scanning keeps popping. The same behavior after I start an application (which uses internet connection) and then I close it. Normally, no WLAN pop should come up. But no, IT comes !

Browsing the internet, I found comment 13 on this post http://www.fring.com/blog/?p=89. It didn't solve my issue, but it blinked a light in my brain! I checked the applications installed by myself and found the sinner: Live Messenger connection was configured to "user defined". Changed to "Always asked" and no more popping! Cute!