I can'd download things - get 403 error - not authorized?

[Jeff]

What gives, suddenly I can't download anything? For some
reason i click on a download link and it boots me to the
403 error, "You are not authorized to view this page"
link.

Any ideas?

 

[H Leboeuf]

Error Message When You Try to Connect to Secure Site: Client Certificate Has
Expired or Is Not Yet Valid
When you attempt to connect to a secure Web site in Microsoft Internet
Explorer, you may receive an error message similar to one of the following:
HTTP 403.17 Forbidden: Client certificate has expired or is not yet
valid -or- HTTP 403 Forbidden You are not authorized to view this page.
http://support.microsoft.com/?kbid=301803 (6/4/2003)

Other issues with 403 errors.
http://www.generation.net/~hleboeuf/403.htm