Going back and looking at Synthrotek's site and the warnings that Firefox pops up on it, it shows that the site contains "unsecured content". The certs for transactions might be secure, but my concern is that there's elements there that clearly are not and which could, in theory, be used as part of a backdooring scheme. Very sloppy in this day and age to put up a commerce website that's not 100% nailed down.
And Jim has a very good point: MAKE SURE your transaction traffic is ALWAYS secure. Check for "https" and NOT simply "http".