Error "Failed to connect. Make sure your device is connected to a same WiFi network"

Hello everyone!
New to the forum, and as bad as I feel to come here and with my first post talk about a bug, I am here to do exactly that!
Got a simple network setup here, PC connected to wireless router, phone connected to the same wireless router. I can ping the phone from my Windows 7 PC, and http://ipaddress worked before, along with http://web.airdroid.com.
I tried for the second time today after this update and it doesn't work anymore! I can still ping the phone, but I get the error showing up in yellow at the top of the screen almost instantly, as soon as I scan the QR code: "Failed to connect. Make sure your device is connected to a same WiFi network." Trying the password instead of the QR code yields the same exact error.
My phone is a T-mobile USA HTC One S. The PC is a fairly well spec'd Windows 7 Premium machine. Router is a standard WRT54G.
Do you guys have any suggestions on how to troubleshoot this? I currently do not have access to other network configurations, as this is my work PC at my office, but I would really like for it to work as it did previously!
Thanks in advance for any help!
Bernardo

I should note I am using Opera. It works on IE apparently. So at least that! But I really hate IE... do you guys think you'll make a version that is Opera tested?
Best Regards
Bernardo

Same problem over here (Galaxy Nexus, Android 4.0.4) connecting to a ThinkPad T520 running openSUSE 12.1 and Firefox 12. Both are in the same network, but fail to connect.

Seconded that! Im using Samsung Galaxy S II with ICS and it worked perfectly, sudenly im getting same error on mine ThinkPad R61, using win7 64bit. Opera or IE or Chrome, it just doesnt work :/ And yes im on same wifi. Anyone got some ideas where is the problem? If i try to connect by IP it shows, that site doesnt exists o.O

can you ping your phone? (start>run>type cmd>type ping web.airdroid.com and see if you get a reply)
if you can't, then there is a connection problem between your pc and phone, maybe a firewall?

I tried a different Browser (konqueror) and the IP-address instead of the address name, and I ws on a different network. This time it worked...

Mine cannot connect with opera using either methods. ping checked

Same trouble with tablet casper android 4.0.3, ubuntu 12.04 and window 7 both 32 bit. Working good with samsung galaxy I android 2.3.6 and same OS on Pc

Hello everyone,
I'm not sure to do the right thing here ...
Connection Samsung galaxy plus with Notebook, Win 7 / PC, Win 7, both firefox: One time it works, than never. Don't know why ...
Somebody can me help?
Thanks!
nutze.die.zeit

I have the same problem. The first time I used it on my Galaxy Nexus with Chrome, it worked great. But after the 1st use, I am not able to get it working again. Not even on firefox. Please fix this problem