Some compression apps don't support Flash Cue Points, so this might help:
FLVTool2 "can calculate a lot of meta data and insert a onMetaData tag. It can cut FLV files and add cue Points (onCuePoint). A debug command lets you see inside our FLV and the print command gives you meta data information in XML or YAML format."
And here's where I'm storing my link to Perian (requires OS 10.4) a plug-in for Quicktime that allows play of files encoded with a non-standard codecs like FLV, XviD, or 3ivX. And if I forget Flash Developer Center.