Iron 19.0.1100.0. for Mac will not run Flash on OS X 10.5. It says Flash is outdated and blocks it from running but OS X 10.5 cannot use the newest Flash. The most recetn version of Flash that will run on OS X 10.5 is 10,3,183,20. This needs to be fixed. Iron is supposed to be compatible with OS X 10.5 and it isn't.