Mounted remote media folder not seen in Windows Media Player

[deKay]

I have a NAS running DSM4.0. I have a PC with a shared folder on it, containing videos.

I can mount the PC's folder in /video on the NAS (either directly *as* /video, or in a folder in /video) OK, and the NAS can see the video files. However, other PCs on the network can't see any of the videos when using Windows Media Player. Media Player *can* see videos I put directly on the NAS in the /video folder, however.

Am I doing something wrong, or is this a limitation?