Same query a George! I've had the setting set to 'Off-Line' for weeks, but I'm still shown as 'Available'!
To both of you, have you asked fellow players how they see you?
Formerly, in Flash, there were two indicators, one on the main profile and one in the left column above the friends list, and only the latter would turn grey when you selected "visible as off-line". Your profile would show green when you looked at it yourself, obciously logged in.
Perhaps, WGT have accidentally kept that discrepancy?