Issue with Firewall Rules

We are having an issue after upgrading to a new ASG525's from an ASG425's (Hot standby on both systems) and from Ver 8.306 to Ver 9.004-16. Because the 525's were new we built them from the ISO then restored the configuration from the last backup from the 425's

When a User/PC/Server connects via the proxy all is ok, all allowed sites can be reached.

If I then create a Firewall rule to allow the PC/Server to access the internet bypassing the proxy I can get to a very limited number of web sites. For example I can get to Google fine, if i then try to go to Yahoo it will just time out. This is the same with the majority of sites that i try to browse.

The filter structure is very simple;

PC1 (Fixed IP address) ------> Any Protocol ------> Internet

I set this as rule 1 then try to access a site through IE/Firefox/Safari and while i can see from the Firewall log the rule is active and working and the IP address of the destination matches the site I'm going to, I just do not get any response back. There is no error from the 525 it just times out.

My guess is that I'm missing something straight forward. I have recreated the masquerading rule and confirmed DNS is working ok.

I have also upgraded to the latest version of 9.

Thanks for any help offered

Ross