cant connect, wrong network

hello,
I use Firefox v19 windows pc and airdroid v1.1.0 beta on android smartphone. both in same wlan network.
I use the directlink http://web.airdroid.com/ like many month ago, I never changed any network settings.
since last week, I cant login via QR Code, it says: "failed to connect. make sure your device is in same network" after QR Code scanning.
manual password tip in is the same.

But the only way is, to browse directly to the IP of the smartphone 192.168.1.2:8888
there is all okay. but so I cant use the QR Code functionaly.

where is the problem??

Buona sera,ho iniziato a collegarmi con il mio dispositivo e il netbook direttamente con l'indirizzo web.airdroid.com, dopo aver scansionato il codice a barre non mi fa collegare, mi dice che non usiamo la stessa rete wifi... dove sbaglio ?