playlist issue

Hello,

I am using the latest player pro on my galaxy s2. i sync my music from my mac to my s2 with doubletwist.not an issue.Today i downloaded an album at work and put it on my phone manually instead of the normal sync which was also fine.However when i put the M3U playlist onto my phone and check it, the playlist doesnt show in the player, in fact the playlist seems to disappear.I have tried saving it on my internal memory as well as my external sd. each time the playlist just vanishes.I never had this issue on my home computer. not sure what the issue is.

Please help.