Playlists getting blanked out?

[pac0naut]

Samsung Captivate : Stock : Froyo : Rooted

Here's what's happening:

-Setup playlist in winamp on my PC using where my mp3's are stored on my phone
-Save playlist
-Put .m3u in my external SD card root
-Plays fine until.....
-I repeat process with adding another playlist
-Previous playlists are now empty.

I've scoured the forums for this. Has anyone else experienced this? Am I missing a step or a process here?