I've not had no issue, watching netflix on windows 7 64bit on fire fox for a couple month. Only thing I notice is, when i watch a series it will auto stop after a couple shows then i only have to restart it.
Yes, ours get about 5 minutes into the next episode and locks up.
Just to clarify, it's watching Netflix on WMC, it works fine on IE.
Is WMC still not working for you? It's been working fine here since yesterday, others are reporting the issue fixed as well:
http://www.thegreenbutton.tv/forums...sid=dfca9ade4e062cdae4355d79ff5260cc&start=20