PLTS HOLDING IN POS ON ACTIVE RWY AT NON TWRED ARPT MAY HAVE CAUSED CONFLICT IN TFC.

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ON DEP FROM LNA I TAXIED TO RUNUP AREA AT HOLD LINE OF TXWY AT RWY 3 AT LNA AND COMPLETED PREFLT CHKS; RUNUP PROC; ETC; AS NORMAL. I HAD 1 ACFT DEPART AHEAD OF ME AND WAITED FOR 1 PLANE TO LAND. I THEN ANNOUNCED ON UNICOM THAT I WOULD TAXI ACROSS RWY 3 TO THE HOLD LINE ON OTHER SIDE TO ALLOW A SINGLE ENG CESSNA BEHIND ME TO DEPART WHILE I OBTAINED AN IFR CLRNC FROM PALM BEACH APCH WHILE ON THE GND AT LNA ON FREQ 127.35. I THEN SWITCHED TO APCH WHILE MONITORING CTAF ON SECOND RADIO. I CALLED APCH AND WAS OFFERED AN IFR CLRNC ON GND WHICH I ACCEPTED. I WAS THEN ISSUED A SHORT DEP HOLD. DURING HOLD SINGLE ENG CESSNA WHICH HAD BEEN BEHIND ME FOR TKOF TOOK ACTIVE RWY. ABOUT THIS TIME I RECEIVED A HOLD RELEASE. I WAITED FOR CESSNA TO BEGIN TKOF ROLL AND TAXIED INTO POS AND HELD. AFTER ANNOUNCING MY INTENTIONS ON CTAF. WHILE HOLDING TO ALLOW ADEQUATE SEPARATION BTWN THE CESSNA AND MYSELF; I HEARD ON UNICOM (UNINTELLIGIBLE CALL SIGN) CIRCLING OVER APCH END OF RWY 3.' BASED ON THIS; I HAVE REASON TO BELIEVE THAT I MAY HAVE CAUSED A CONFLICT BY TAKING THE ACTIVE RWY. 15 SECONDS FOLLOWING THIS; I ANNOUNCED '(MY CALL SIGN) DEPARTING RWY 3' AND BEGAN TKOF. I HEARD NO FURTHER CALL FROM CIRCLING ACFT BEFORE CONTACTING PALM BEACH APCH WHEN AIRBORNE. I ALSO POINT OUT THAT I HEARD NO CALL FROM ACFT WITH CONFLICT PRIOR TO THE CALL ANNOUNCING 'CIRCLING OVER APCH END RWY 3.' I ALSO VISUALLY SCANNED THE APCH PATH PRIOR TO TAXIING ONTO RWY 3 AND SAW NO ACFT AT THAT TIME. IT IS POSSIBLE THAT THE ACFT WAS AT AN ALT OF 1000 FT AGL WHICH WOULD HAVE PRECLUDED EASY SPOTTING OF ACFT. AS WAS STATED; I WAS UNABLE TO DETERMINE FROM RADIO XMISSIONS IF IN FACT ANY CONFLICT OCCURRED OR IF THE CIRCLING WAS A MANEUVER TO GET INTO POS FOR AN APCH; ETC. IF THE EVENT IN QUESTION WAS A CONFLICT; THERE APPEAR TO BE A SUBSTANTIAL NUMBER OF CAUSES.