I haven't noticed this before, but since I haven't really shopped here much lately, it could be that I just haven't paid attention and that it's been going on for weeks. However, right now, chrome does not consider your HTTPS content to be satisfactorily encrypted, which is making me reconsider whether I want to finish my purchase or not.

When I use an encrypted site, my address bar should show a green lock indicating that the site is truly secure (using chrome browser). Yours does not show this, instead, it is plain white. At the very least, you are loading content that isn't encrypted (your renderosity logo on this page, and then some advertisements from filterforge on the checkout page, both of which are loaded with the unencrypted http protocol. )

Most things appear to have been done properly, so I'm guessing it's just some recent changes that broke things, but it's a very serious breach of trust and indicative of either sloppy work or the work of an inexperienced programmer both of which make me nervous to enter credit card stuff.