timppu: Are you using web browser or the Galaxy client?
If a web browser, what web browser?
If a web browser, are you using some fancy adblock antigovernment cyberninja software?
If a web browser, have you tried another web browser with its default settings (without using any additional "security" or "hide-identity" software, and not touching the cookies and shits settings)?
Oh, and to answer your question: No, I haven't seen that same problem. I am using the Chrome (or at the moment, Chromium in Linux) browser with default settings.
EDIT: Also, when you say you go to "make a wish for a game", do you mean going to add a game to your wishlist, or create a wishlist entry like "I want System Shock 3 to GOG.com, please?".
Mostly just using a Firefox browser with the latest updates and last few times my adblocker has not done it to before, so it can't be that, and yes when i go to add it to my personal wish list it says i need to sign in......