I like many other people who own a WD media player and have Windows 7 had trouble getting my player to connect with my network shares. Every time I would try to connect it would tell me my password was wrong. Turning off password protection in Windows wouldn’t even help. After many hours of frustration and trying different fixes people posted on here, I’ve finally found the fix. Go into add/remove programs and remove Windows Live sign in. For some odd reason this program doesn’t like to play nice with WD TV Live. I recently purchased a Hub for my parents and this program actually caused the network shares not to show up at all. Hope this helps some of you guys pulling your hair out and getting ready to chuck your player across the room.
It’s been a long-standing issue. It has been fixed on the Live / Live+, but we haven’t seen a new FW for the Hub yet since then.
The Live Sign-In Assistant / Essentials 2011 thing does NOT affect the ability to FIND a share, only log into it, so your latter point may have just been pure coincidence.