Wow. I've been buying off and on from GMG whenever they've had a sale, and I've never had an issue, and I live in Canada. What type of credit card do you use? Whenever I buy anything from them, their website takes me through the Mastercard Securecard feature which is linked to my bank. I have to re-enter another password in order for my credit card order to be accepted. I wonder if that's a reason why people are having difficulties.
Holy fuck, the Green Man Games site isn't lying about some banks flagging their site as a gambling / fraud site. I got an email from my bank minutes after making my purchase letting me know that my card had been limited and to call the fraud hotline.
Then they asked me random questions like... name some cross streets and nearby landmarks. Naturally, I work from home and don't drive so I was like... um, I have no idea. Ask me something related to my account lol. That was an awkward phone call.
Or maybe, since I've lived and used my card out of the country before, my bank knows what my spending patterns are already, which is why my purchases aren't flagged normally.
*knock on wood*