intermittent problems with public hotspots

Hi I got a couple problems that I think may have more to do with the
settings on my laptop than any 802.11x protocol bugs :


In short, If, once you connect to a hotspot, what stops you from
accessing http, mail, or both?

e.g. in the dubai business lounge at the international airport I could
connect to the AP (hotspot) but could not access mail, or the web. At
other places like Mornington Maccas I could use Outlook but not IE, and
vice versa at Mnt Martha.

Am using XP on a brand new laptop, and have the latest updates for the
centrino chip etc.

Regards
Henry