New bug - Turn off Wifi and System hangs!

This is a repeatable problem:

Every time I turn off wifi on my MBP running 10.9, the system hangs. The only way to recover is to reboot. The interesting thing is that my MBP is hardwired to the internet which is why I an turning off wifi.

Anyone got a solution for this? I just want to be able to turn wifi on and off without a system hang.

P.S. I did start in SAFE mode and try to turn off wifi but the system hung there as well.

UPDATE: Though it is not a fix, I found the following command line instruction to turn wifi off using TERMINAL: networksetup -setairportpower en0 off

It worked but, again, haven't a clue as to why, out of nowhere this would become a problem. I guess it's just Vista, er, I mean, Mavericks acting up.

 

Thanks

Much appreciated.