BIS over WIFI works only with connectify software

I usually use the office WIFI AP while I'm in office, it had no problem until today.

Today after I turn on WIFI and connect, it shows that WIFI did not get BIS, but I turn on my laptop then us my laptop to connect to office AP and run connectify software, then connecting my blackberry to connectify, BIS works.

So my blackberry can get BIS over my laptop through my office AP, but can not get BIS directly from office AP.

I'm using bold 9780 with latest OS 6.0, and I tried

1.battery pull
2.reset the wifi setting
3.reconnect server times

But it's not working at all, anyone can help me on this?