I decided recently to take the plunge and upgrade to Lion. As my computer had previously been running Leopard, I first had to upgrade to Snow Leopard, so after ordering Snow Leopard, installing it, and upgrading it to 10.6.8, I got onto the Mac App store and was ready to download Lion. But for some reason I cannot sign into my Apple ID account. When I log in, in seems to recognize me and then it just asks me to sign in again. Any solutions?