I have a suspicion about what has happened, but it wouldn't be prudent for me to elaborate here.
Just change the password on your PC as mentioned above. It will automatically be the same for ipad.
While you're at it, make the new password a strong one, at least 8 alpha-numerics with upper/lower case and at least one special character. There have been numerous reports of account hacking/stealing credits.
WGT doesn't recognize all special characters, so just keep trying a different one until it takes.