PLT RPT; EMB120. PAX LAPTOP COMPUTER AT ROW X POSSIBLY INTERFERED WITH VOR NAVIGATION. CAPT HAD PAX'S COMPUTER SHUT OFF; NORMAL NAVIGATION RESUMED.

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I EXPERIENCED INTERFERENCE WITH VOR NAVIGATION RECEPTION. WE FOUND A PAX IN SEAT XA; OPERATING A 300 MHZ TOSHIBA PROTEGE LAPTOP COMPUTER. WE HAD HER DISCONTINUE USE OF THE COMPUTER AND NORMAL RECEPTION WAS RESTORED. I HAVE HAD PREVIOUS PROBLEMS WITH TOSHIBA COMPUTERS THAT ARE USED IN ROW X. I WILL NOT LIMIT THE USE OF PAX ELECTRONIC DEVICES YET; HOWEVER I NOW IMMEDIATELY CHECK TO SEE IF A LAPTOP IS ON WHEN EXPERIENCING NAVIGATION PROBLEMS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT THE SAME EXACT INCIDENT OCCURRED ON A DIFFERENT EMB120 AT ROW X AND WITH A TOSHIBA LAPTOP COMPUTER. THAT TIME; THEY WERE AT MCCALISTER VOR; WHEN THE VOR NEEDLES ON THE MFD (MULTIFUNCTION DISPLAY) WENT CRAZY AND WERE SPINNING IN CIRCLES. IN BOTH CASES; IT WAS SPINNING IN CIRCLES ON BOTH NAV 1 AND NAV 2. THE RPTR GUESSED IT WAS A LAPTOP COMPUTER CAUSING IT AND HAD THE FLT ATTENDANT CHECK IT OUT AND HAD THE PERSON TURN IT OFF. AFTER THE VOR RETURNED TO NORMAL; THE RPTR ASKED THE FLT ATTENDANT TO HAVE THE PAX TURN IT BACK ON TO SEE WHAT WOULD HAPPEN; AND THE INSTRUMENTS RESUMED TO ALMOST A NORMAL POSITION; BUT IT WAS 40 DEGREES OFF FROM ATC. HE SAID ROW X IS THE FIRST ROW BEHIND THE TRAILING EDGE OF THE WING; AND SPECULATES THIS MAY HAVE SOMETHING TO DO WITH THE WING'S WIRING OR AN INSTRUMENT UNDER THE WING. WITH THIS PARTICULAR INCIDENT; HE IS 90 PERCENT SURE THAT THE PAX DID TURN HER COMPUTER BACK ON AFTERWARDS; BUT THEY WERE ALMOST ON TOP OF THE NEW VOR; SO HE BELIEVES THAT'S WHY IT DIDN'T INTERFERE AGAIN WITH THE NAVIGATION. THE RPTR SPECULATES THAT PERHAPS THE TOSHIBA LAPTOP COMPUTER AND THE VOR HAD THE SAME OR SIMILAR FREQUENCIES.