Bizarre no compile constant error in OSX

Im a little stunned in discovering this, I dont know if a lot of people already know this or no, but happened something very strange with me now, Im happy to have discorered it quick and not spend a lot of hours with this ridiculous situation, but something happened to me:

When I was doing a site work, I save a LOT of backups. This site work was a lot messy, and by hurry I did placed the swfadress class in there. When I did saved another backup in this folder, the flash did not compile with swfadress anymore, error of compile constant thing.

Why?

Well, for what looks like to me, the folder was with 129 files inside it. Up this number, the things does not runs well. So I placed some old backups in another folder and now the things are doing right.

Strange hun?