Solution
How To Install Your Thawte SSL
Thawte SSL requires a intermediate CA certificate to be installed together with the CRT and Key.
You can refer to this URL for the installation guide:
https://search.thawte.com/support/ssl-digital-certificates/index?page=content&id=SO1498&actp=LIST&viewlocale=en_US
For quick reference, here are the direct links to the Intermediate Certificate
SSL123 Intermediate CA Cert:https://search.thawte.com/library/VERISIGN/ALL_OTHER/thawte%20ca/SSL123_CA_Bundle.pem
Webserver Intermediate CA Cert:https://search.thawte.com/library/VERISIGN/ALL_OTHER/thawte%20ca/SSL_CA_Bundle.pem