iTunes 10- won't recognize shared libraries/shared libraries not showing up
Basically, I have this computer authorized to share both of the libraries off of the other computers, but I get no "shared" tab when the libraries are open and should be accessible. They work just fine on the other two computers, and the library from this computer shows up on them. I'm using iTunes 10.0.1 on this computer, the others are running the last version of iTunes 9 from just before Apple came out with 10.
I have tried restarting the computers, restarting iTunes, and uninstalling and re-installing iTunes on this computer and none of it has worked. I also tried looking at the help files because on the drop-down I noticed one titled "If you don't see shared libraries" but the iTunes help box only shows up blank and then gets stuck searching when you try to look something up (which isn't an issue with the help tab when "finder" is selected).
How can I get these libraries to show up? I'd really like to have this work so I can listen to my music in other rooms, but so far I'm having no luck.
MacBook Pro, Mac OS X (10.6.4)