Why can I access my website normally but some users can't?

I cant access one website, my work portal however can access any other website secure or not.?

• I cannot access my work portal website from my connection at home while I can access it anywhere else. The website is https://sgdaus001.csc-fsg.com/ its a website for the Sun global desktop which allows me to access my work desktop from home. Please read what I've tried so you just suggest the following. Also, I have A+ hardware and software certifications, so please keep in mind when giving obvious suggestions. Here is what I have tried. The connection I use is a direct local connection from cable modem. I've tried the following - 1. Unplug/plug the modem. 2. Reset the modem. 3.Called service provider and made sure website wasnt blocked. 4. Got service provider to resend signal. 5.Tried turning firewall, pop up blocker etc off. 6. Checked settings cleared internet cookies, temp files, history. 7. Tried 3 different browsers Chrome, Internet Explorer, and Firefox. 8. I can access any other secure website, I've also added this website to my secure sites list. 9. Tried a system restore to the point when it was working. 10. This doesnt work on my machine or the laptop on the wireless. It is not the wireless router because I have connected directly to the modem with no success. 11.Because it works on neither machine, i established it has to be the modem or something both machines share. 12. The website requires JAVA I have the latest version. 13. Dont see anything blocking this website checked off. 14. This is a valid website, try the link. Works from anywhere else on my machine. There is no website maintenance going on. Anybody have any suggestions? PLEASE HELP IM GOING CRAZY I CANT WORK FROM HOME!!!!!

• Answer:

  That site has an invalid security certificate. That's the fault of whoever maintains the site, not you. Call your IT department. The certificate expired on 7/15/2009. Possibly, your software elsewhere didn't check the certificate very often, and continued to allow you access. To validate that this isn't the fault of your home connection, take your laptop to a public library or Starbucks or someplace with free wi-fi. Most likely, it will get to the internet, but not to the work portal. If you just take the laptop to work, that's not a good test, because then you'll be logged in on their intranet, and will not have to VPN in.