ID or Password is incorrect Issue

I am able to log onto the forums with the same password and ID but when I try to log into the game it doesn't let me. I have not switched my password and was able to log in about 2 hours ago with no problem. Now this error is popping up for me saying my ID or Password is incorrect. I asked my brother to log on to my account and he did it fine but I cannot. My friends at my place cannot log into theirs as well. Please let me know if this is a network issue or a server issue.

Thanks!

check that your shift key is not stuck.

also if your input language has changed, this will cause characters to use a different encoding which might not be compatible with the login ui used (its IE based)