Checking the end of FLV Playback

Is there any special trick to accurately getting the end of flv playback event? I have to build a player that’s also flash 7 compatible, which has an onEnterFrame in it that updates a progess bar. The bar calculates the ns.time/duration to figure the position in the video, but it NEVER gets to 100% with any flv I try - Ususally somewhere in the 98.5 - 99.5% range. Is there a clean way to detect when a video has complete playing?