I had a User Profile problem. the user GPO wouldn't load every time so settings was not being applyed. this was all random anyways it may help it may not but when i checked my event log it told me gpo wasn't applyed because of a possable dns problem.
Edns
read this post and turn it off and see if it sorts any of your problems out.
support.microsoft.com/kb/832223
For Windows Server 2008 R2
DNSCMD is installed by default on Windows Server 2008 R2 DNS Servers. At a command prompt, type the following command, and then press ENTER:
dnscmd /config /enableednsprobes 0
Note Type a 0 (zero) and not the letter "O" after "enableednsprobes" in this command.
This worked for my problems with windows 7 and more little ones around the network
