Strange DNS issues, ping, resolve but no browse or mail?

I've been at this for days to please bear with me.

Intermittent Windows SBS 2008 DNS issues over the last couple weeks.
Using forwarders they resolve as do domains from the lan.
I even have the UT pointed back to the sbs dns and it resolves fine.
Trouble is when you browse the site will not resolve and just times out.
Mail is also not making in it or out.
Have tried multiple nic's on the SBS.
Used fixed my network and all looks ok.
Ran the sbs best practice analyzer and no critical issues.
Tried a couple different switches, cables etc.
ISP is fine-plug directly into the modem and am able to surf.

Was running an older version of UT 9.? and one of the resolutions a week ago was to check DNS Bypass.
It was time to upgrade so installed a fresh copy of UT 11.
I installed OPVN, Web Filter lite, intrusion protection and reports. All are off for testing.
DNS Bypass is checked
Wan, Lan and DMZ/interface gamma
Static IP's -couple alias and port forwards to sbs server for mail and web.

I'm really, really lost on this one.
And I know if we're not up tomorrow its going to be a bad, bad day

Any help or guidance would be greatly appreciated.

Thanks
TL