The style seleciton in the Forum Edit profile screen should actually have been removed altogether in Nuke6.5
All theme selection in Nuke6.5 should be done through the Your Account Theme Selection.
You might see some adverse affects if you start trying to change themes from the Forum Profile. We removed the script from ours that saves that info to the database. The selection is still there on this site, but it doesn't write the value to the database which is what you want.

If a theme is made properly for Nuke6.5 then changing themes though Your Account should work perfectly.

mikem