I have 2 computers in hand both have Office 2010 32bit installed.
When I try to authenticate my Facebook acount on my WinXP SP3 it works, when I try to authenticate my Facebook account on my Win7 64Bit - it fails.
I constantly get a wrong username\password message - although the same credentials worked on my WinXP computer.
I have also tried to authenticate with other accounts - and it doesn't work on Win7 64Bit.
The Windows Live and LinkedIn connectors work great for me - just the Facebook fails authentication.