Home Sharing disappears on ATV

I'm having issues with my 2nd generation Apple TV "home sharing" with iTunes on my Windows PC.

About two weeks ago, after Home Sharing working fine, the library will no longer appear in the Computers of the ATV menu.

Both are running the latest software (iTunes 11.0.5 and Apple TV 5.3) and are using the same Apple ID for Home Sharing. I've turned Home Sharing on and off multiple times on both devices with no luck. The firewall doesn't seem like the source of the bug either. Hopefully, Apple's new update supposedly coming September 18th will fix the problem....