| I saw this at zune online.
Why doesn't media from my network share play on my Xbox 360 console?
If you added a network share to the monitored folders list in the Zune software, the files might not play on your Xbox 360 console. This problem is most likely related to access permissions.
The Zune software uses Zune Network Sharing Service (Zune NSS) to share media. Zune NSS runs under the Network Service account rather than your user account. Therefore, the remote network share may not allow Zune NSS to access the files.
To fix this problem, modify Zune NSS to run under your user account, which will give it the same access you have to the network share.
This change is not recommended if multiple user accounts on the same computer are sharing media from the Zune software, because there is only one Zune NSS for all users on a computer.
Change Zune NSS access
On your computer, click Control Panel, Administrative Tools, Services. If you are running Windows Vista, you can see Administrative Tools in the Classic View of Control Panel.
Right-click Zune Network Sharing Service, then click Properties.
Click the Log On tab, then type your user name and password in the boxes.
Restart the service. | 
