This happens to me at work too. Your company is using a caching proxy of some sort. If you hit the browers refresh it should show your data... Sorry I can't give a better tech explanation, not my area of expertise
This isn't my area of expertise either, but if you add a fake argument to your URL string like "&foo=bar" that should probably force a non-cached version. I'd check to see if there are any extensions available for your browser that do something like that.
we can only use internet explorer and i don't have admin access
So now you know that others in your company (or at least behind the same caching firewall as you) are HN users! :)
i see. i suppose that's why when i hit different links (e.g. ask, submit) i see different karma numbers unless i hit refresh