There may be some compilation warnings due to bugs in GNU flex and libupnp. They can safely be ignored.
Unfortunately the NETGEAR MP101 is quite buggy, even with the latest firmware (1.3.7 as of writing this). Numerous forum posts on the internet can confirm this. For me, it seems to hang randomly when browsing or when just about to play a song. I have yet to discover what is causing this.
If you need to listen on more than one interface, you will have to start multiple instances of the media server.
GMediaServer keeps information on all audio files in memory. If your audio collection is huge, this might be a problem.
As GMediaServer is in an early stage of development, many essential features are unimplemented.