Ok here's an admin-level response:
It seems that your browser is blocking referrals. This is comparable to blocking icmp traffic. Are you using some kind of personal firewall/security?
For example:
Here's instructions how to bypass this 'feature' in norton personal firewall/norton internet security:
http://www.virginblue.com.au/help/norton.html
...this sort of thing does explain most of the reports I've been getting.
thanks.