Well, Apple just released the latest version of iTunes, 4.8.

I was hoping some improvement in network share/playing. I found it. At least so far. I was having problems with 4.71 having issues. My music server is on my window box, running iTunes share, and sometimes my Mac (where I do all my work) sometimes got an error saying that it was not accessible.

All this seems to have been solved with 4.8 so far!