I went to ebay.ca to pay for an item through paypal i won, (which i have done many times) and a securiy alert came up with three symbols the first was with a green checkmark saying "The security certificate is from a trusted certifying authority.
The second one was with a yellow sign stating "The security certificate has expired or is not yet valid. and the third one was with another green check saying "The security cert. has a valid name matching the name of the page you are trying to view.
What does this all mean, i've been using ebay for quite some time now and never have i seen this.

Thanks

The following is from Windows Intenet Explorer, version 7.0 Help Menu: About certificate errors

A certificate is an electronic document that can help identify a website's owner and can help you make decisions about trusting the site with personal or financial information. Certificates are issued by certification authorities whose responsibility it is to confirm the identity of the website owner or organization.

Why do certificate errors occur?

Certificate errors occur when there is a problem with a certificate or the server's use of the certificate. Internet Explorer can help keep your information more secure by warning you about certificate errors.

How do I know if there is a certificate error?

Usually, a blocking page will appear that will warn you about the problem with the certificate. If you choose to ignore the error and continue, the Address bar will turn red and a notification will appear in the Security Status bar (next to the Address bar).

I'm getting errors on websites I always visit, what should I do?

If you encounter a certificate errors at a website you have visited before without errors, it's possible the website is not configured correctly. Try retyping the address you are using. For example, if you are typing the address as https://example.com, try changing it to https://www.example.com.

I think this is the most likely cause:
It is also possible that the website's certificate has expired and the owner or operator needs to renew the certificate in order to continue using it.

Is it ever safe to ignore a certificate warning and continue to a website?

A website's certificate provides identification of the web server. If the certificate has an error, it might indicate that your connection has been intercepted or that the web server is misrepresenting its identity.

What happens when I continue to a website that has a certificate warning?

If you ignore the warning page, and continue to a website that has presented a certificate containing errors, Internet Explorer will remember the certificate. You will not get error for that certificate until Internet Explorer is restarted.

What do the different certificate errors mean?

The following table contains a list of common certificate errors and information about what they mean.

Error message What it means
This website’s security certificate has been revoked Do not trust this website. This error message often indicates that the security certificate was obtained or used fraudulently by the website. The encryption key that is specified in the certificate might have been compromised or the user listed in a certificate does not have authority to use it (for example, the company was sold). The certification authority that issued the certificate keeps a list of revoked certificates and that list is checked by Internet Explorer.
This website’s address does not match the address in the security certificate This error indicates the website is using a digital certificate that was issued to a different web address. This error can also occur if a company owns several websites and uses a certificate that was issued for one web address for another site (for example, for a different department or division).
This website’s security certificate is out of date This error occurs when the current date is either before or after the time period during which the certificate is valid. Websites must renew their certificates with a certification authority to stay current. Outdated certificates can be a security risk. After a certificate expires, the Certification Authority that issued the certificate is no longer responsible for ensuring that the certificate is not misused.
This website’s security certificate is not from a trusted source This error occurs when the certificate has been issued by a certification authority that is not recognized by Internet Explorer. It is unlikely that this error will occur on a legitimate business or banking site. Phishing sites often attempt to use fake certificates that will trigger this error.
Internet Explorer has found a problem with this website’s security certificate This error occurs when Internet Explorer finds a problem with a security certificate that does not fit any other error conditions. The error can potentially occur because a certificate has been corrupted, tampered with, is written in an unknown format, or is unreadable. You should not trust the identity of the site if the certificate has this error.