I'm getting an invalid certificate error on https://www.elance.com
Is that normal or is it just my machine?
elance.com is presenting a certificate for akamai.net rather than for itself. Akamai is a well known Content Delivery Network used by many websites to spread the load of servicing many users. It's likely that elance.com contracts with Akamai to provide CDN services and there is some misconfiguration where pages on elance.com are being served by Akamai but elance.com is presenting the certificate belonging to Akamai rather than their own. Since certificates are tied to a specific domain name, anything appearing to come from domain A but with a certificate from domain B is going to be flagged as using an invalid certificate.
In short: you probably have nothing at all to worry about; someone goofed.
It's not just you.
IE 9 says that "The security certificate presented by this website was issued for a different website's address."