m3u files are like notecards, a simple file that lists the titles of the songs and points the player where to find them. If the actual music files have been moved from where they were, then the m3u file won't be able to find them when you try to open that m3u playlist file up in any player.

It's my guess you are adding the songs to a playlist in the LW media player, then saving that as an m3u playlist file.

For fast & easy access, go to your LW Library window, select Saved Files folder & press the Explore button. Sample image here: Using Library Explore button to access downld folder (click on link) & the folder will open up for you.

Also, if you hover your cursor next to the shared / saved file listing in the Library window, this will show which directory it is in. eg: C:\Documents and Settings\"your account name"\Shared

So direct your other player to find them there. Else, move the music files to your account Music Folder and add them to your player from there.