OK, I have an odd one here and I hope I can describe it properly. We have our staff and pupils separated with a one way trust and each has its own web filter. It's the same product but a different installation of it. Since Google forced secure search by default we discovered that pupils were getting unfiltered access to Google searches. The filter kicks in so they don't get access to the sites but they get the results because the filter can't interrogate a secure site to filter the searches. I'm sure you appreciate the repercussions when it comes to image searches!
Our proxy (Smoothwall) allows a content modification that forces safe search to force the usual filter level measures and in the staff it works perfectly; staff cannot get to secure searches and the higher security levels are applied. The problem for the pupils is that this measure works...for everything except Google. The pupil PCs refuse to use the unsecured site for searching so we've had to block most of Google to protect the pupils. What happens is when we try to enforce it, it looks like the page constantly refreshes but what's really happening is it's switching between http and https; the proxy switches the secure site on and the browser wants to return to secure, so Google is unusable.
We thought it was down to Google but we've checked and the staff PCs definitely work the way we want them to. We tried using a different search engine for the pupils and it works. We then tried using Firefox portable and that works too! So we've got it narrowed down to something in the Internet Explorer settings. We only support IE though (currently they are all on version 8 but we tried updating one to 10 with the same result) so we can't just do a blanket install of a different browser. We've ruled out the filter too because we can put a staff PC through it and Google searches unsecured. We think it must be something in the Group Policy because they don't apply to other browsers and when we tried a fresh PC image with no policies Google behaves. It has to be something in policy but we have no idea what. We're trying to add the policies one at a time but that will take a while so I'm hoping someone may be able to point me in the right direction.
Has anyone comes across anything like this before or offer any suggestions that could be causing it? I can find lots of complaints about Google's default setting and other establishments that have had to block Google but nothing pointing to this particular "flashing" issue.
Any suggestions would be appreciated.