Wanted to buy a few games, then at the check-out page the URL was red (Firefox) meaning something is off with the secure/encrypted connection. I've never had anything but green, meaning ok, before.

In the status view of the web-page it said that there's no specified verification of the certificate and that the connection is partially encrypted and that information sent over the internet without encryption can be intercepted by other people while in transit.

Never seen this before at GOG so I'm a little sceptical, and paranoid, these days. And I never purchase at any site unless the https/encryptions shows a-ok in green.

It has to be some recent site update. The same situation on Account page. See this post
http://www.gog.com/en/forum/general/gog_com_account_not_https

Ahh, ok. Seems they are working on it. Just hope they fix it before the sale ends. No matter how secure it seems to be I'm not taking any chances. :) Thank you for your reply.

Good luck in convincing some people of that, some people are obsessed with the shiny green icon (not even the blue one is good enough for some people). The warning clearly states that only 'part of the site' is retrieved from a non-encrypted source, usually the images (or that has been my experience as a server admin).
Note, this is me talking about this in general and is not in any way meant to insult anyone on this forum. I just got flashbacks to a particularly irritating customer I had to deal with last year with this same issue.

It's not merely "some browsers being overzealous". Every browser should give this warning, unless the user has disabled it. (These warnings are so common and annoying that most users disable them forever in their first session on a new desktop.)

The fact that a particular connection is encrypted and secure does not mean that the entire page is encrypted and secure. The checkout page does contain unencrypted content, consisting of links to images and other gog.com content. A browser correctly displays the "encrypted page that contains some unencrypted information" and "you are about to leave an encrypted page" warnings when you navigate to or from such a page.

But those warnings are harmless. If, on the other hand, you were to get a "information you have entered is to be sent over an unencrypted connection" warning, you would be justified in raising an alarm. Since the gog.com checkout page gives no such warning, Venom's assurance that the connection is a secure one is true.

With Ajax stuff you will almost always get this warning. No need to encrypt all the page's assets (images and such) I think that's what you're getting. I've bought stuff in the last two weeks, no issues.

You sure? Generally browsers don't give warnings about harmless. It's harmless in terms of GOG, assuming that the site has been visited by a direct route. If someone has found an XSS vuln in GOG (and presented someone with a nasty link), then it's a totally valid warning that they may in fact be in control of your browser, and the payment screen you then go to won't be GOG's (though they'll take your payment details all the same).

FWIW I did not get this warning with FF 3.6 (latest patch) 2 weeks ago.

The situation you describe would not give that warning; it would give an "information to be sent over an unencrypted connection" warning.

Browsers give numerous warnings about conditions that are benign and related to Web sites that were designed without complete and thorough attention to security. This is probably unfortunate, because it entices users into ignoring most of them, or setting their browsers to ignore them. It is also difficult for mainstream users to tell the difference between a benign condition and a dangerous one, from the jargon in the warning message. Probably because that warning is "off", either by default or because you turned it off earlier. Check Tools->Options->Security->Settings. The warnings that are enabled vs. disabled are listed there.

Good call, I turned it off, probably ages ago.

I use IE8 and I'm sure I didn't have such warnings until yesterday. So there has to be recent change on site.