Web server not available for everyone...

Hi. I have a strange problem currently going on with a webserver I recently set up for a company. I can access the website from every computers I tried, except the computers from my college. For some reasons , they can't connect to the website. I though this was due to some restriction within the school, but the problem seems to appear at different place. I recieved calls telling me the website was unavailable while I tried by my own and could connect without any problem. I don't know if this is this occur from a specific ISP or on a specifig behavior, I can't figure out what is going on.

for reference, the website is http://www.globnor.com . Tell me if you can connect to it and/or you have any idea on why this strange behavior occurs. Thank you!