Connection is fine. Here are some more clues. I think it has to do with some firewall settings with my employer. I seem to only be running into issues while at work. I noticed a lot of content, especially images, used in the forums are stored at content.invisioncic.com. Sometimes links to this site work and sometimes they do not - they are refused.
Chrome has the following suggestion:
Allow Chrome to access the network in your firewall or antivirus settings.
If it is already listed as a program allowed to access the network, try removing it from the list and adding it again.
So I'm currently investigating that. Have you ever seen that type of issue before ?