my girlfriends p10 has done this since the day we owned it.. some times its gone for months, sometimes it happens every day for a while..
one thing i did notice tho is it really depended on the key we used.. if i used my copy which is some cheapo copy from some store the dummy lights are more likely to stay on, if i use the original key its ALOT less likely to happen..
i've always assumed it was an ignition switch problem..
edit: also more recently i have discovered pushing the brake or clutch pedal Can make the lights go off.. not sure why.. but it works more often then not