Airplay speakers icon is missing, cannot change speaker output

We have the same issue. One desktop running itunes 10.2.2.14 with a LAN connection has no airplay icons at the bottom right and will not connect to airport express. The other desktop (running itunes 10.2.0.34 with a LAN network connection) and a laptop (running 10.2.2.14 on a wireless network connection) both on the same network & both have the airplay speaker icons and work perfectly with airport express and both iphone4's. I tried re-installing itunes & re-booting the PC and it did not work. I also tried adjusting the firewall settings, but to no avail. I will re-boot the network and unplug the airport but I don't imagine that it will help as everything works fine except for this one copy of itunes. I was thinking of trying to roll back to a previous version of itunes until I realized that the laptop was running the same version and it worked fine there. Itunes on this PC does not show the option of “Look for remote speakers connected with AirPlay.” under preferences. It only has a check box for "allow itunes control from remote speakers" and that is checked. I have been through all the menu's looking for the other preference option (as indicated in the help file) but it is not there.

Additionally, the iphone 4/ipod that is paired with the non-airplay copy of itunes DOES have the airplay icon on it and will work with airport when using the ipod or when using the remote app to connect to another itunes library on the network, just not when attempting to connect with the library in the non-airplay version of itunes.

After spending this long on an issue I usually get it figured out, but I am super stumped....

and right afterI post i find this...

AirTunes speaker menu missing from iTunes for Windows

If your firewall is blocking the port that iTunes uses to locate AirPort Express, then guess what--you aren't going to see the speaker menu. Fixing this is as easy as opening the right port on your firewall.

Products Affected

AirPort, iTunes

iTunes uses UDP port 5353 to locate AirPort Express base stations that can be destinations for your AirTunes music stream. Make sure this port is allowed through your firewall.

You can learn more about the TCP and UDP ports used by Apple products here.

I have the same problem but I don't have the Osx Lion firewall activated.

I have tried to locate the problem with no avail.

The airplay speaker is connected on the same wifi as mine, I can ping it so this does work as expected.

What is more strange is that some days ago it worked as expected and I don't remember updating iTunes, I'm currently at version 10.5.2 64 bits.

Does anybody have some solution?

Ive also got the same problem. Everything working fine at Christmas, went to play music through my new zeppelin air speakers and no can do! Nothings been changed since i originally set them up. Have the latest iTunes installed, have turned everything off and on again..... At a loss as to what to try next.... Network all fine, speakers can see the network, just iTunes can't see them! Very frustrating!! Anyone know why I should try next?

I just bought the Zeppelin as well and I have exactly the same problem. My iTunes won't give me the airplay symbol when I start up the program.

Any suggestions?

And I'm using iTunes for Mac.