Homesharing doesn't stay connected...

I've established the connection between my iMac and Macbook Pro.

I see "homesharing" on the left hand side of itunes.

But the other computer doesn't show....

UNLESS....I reboot my router....

Then it will show for a couple of minutes but then times out.

Any suggestions on what settings I have wrong in my router?

I have a WNDR3400v2 Netgear router.

I have OSX 10.8 on both machines and iTunes 10.7.

Thanks!