I have searched ALOT, and I haven't found a solution that works. I have tried to turn off my firewall + antivirus (Avira and McAfee) and even uinstalled it, but it didn't work. The problem started first when I tried to update to 1.5.2.
Last things that I can think of that might affect your problem:
1) I suggest you try updating LWJGL.
2) Look at this thread.
Updating didn't work, and I couldn't get in at the website at 2). But what I found out was that I could choose to not update, and then just wait. It turns black, and then the Mojang logo comes up and BAM, im in. Thanks anyway!
Someone help me... please?