THE LEFT HEADLIGHT WILL SUDDENLY GO OUT, SOMETIMES WHILE DRIVING AND OTHER TIMES THE HEADLIGHT WILL NOT LIGHT WHEN THE VEHICLE IS STARTED. AT TIMES IT REMAINED OFF FOR ONLY A FEW MINUTES AND OTHER TIMES IT WILL BE FOR DAYS. I'D TAKEN THE VEHICLE IN FOR SERVICE, BUT EACH TIME I DID, THE LEFT HEADLAMP WAS AGAIN WORKING. I'D ALSO REPLACED THE HEADLAMP IN QUESTION, BUT STILL THE HEADLAMP WORKED ONLY INTERMITTENTLY. I JUST RETURNED FROM MY 4TH VISIT TO THE DEALER, AT WHICH TIME THEY REPLACED THE LEFT FRONT LIGHT BALLAST ($440.00). THE HEADLAMP IS CURRENTLY WORKING. MY WIFE HAS BEEN RELUCTANT TO DRIVE THE VEHICLE AT NIGHT, FOR FEAR THAT BOTH HEADLAMPS WOULD GO OUT. IN RESEARCHING ONLINE, I'M FINDING THAT THIS HAS BEEN A RECURRENT PROBLEM WITH 2004 AND 2005 VOLVO XC-90'S. I UNDERSTAND THAT THE NHTSA HAS BEEN INVESTIGATING THIS PROBLEM WITH THE VOLVO XC-90 AND A RECALL IS BEING CONSIDERED. WE PURCHASED THE VEHICLE PRIMARILY DUE TO IT'S 5-STAR SAFETY RATING, BUT WE ARE NOT CONVINCED THAT VOLVO HAS ADEQUATELY ADDRESSED A KNOWN PROBLEM. *TR