m3u imported list doesn't play

Having the same issue. I believe the fault lies with Winamp for this one.

The process:
File -> Import Playlist -> Select .m3u playlist created in Winamp -> Select playlist in tab -> Play -> Error Message

Unfortunately I disabled the error message but it said something to the effect of "...cannot find core..."

Opening the m3u playlist in Notepad I see that it only includes a partial directory. So Songbird is able to load the filename but not a link to the actual file. Looking for a workaround.

Ok. I figured it out! Winamp only exports part of the file location. For example:

The file location is:
E:\My Music\Depeche Mode\Depeche Mode - Music For The Masses\Depeche Mode - 01 - Never Let Me Down Again.mp3

Winamp will export:
\My Music\Depeche Mode\Depeche Mode - Music For The Masses\Depeche Mode - 01 - Never Let Me Down Again.mp3

Note the lack of the root directory (in this case, E:) in Winamps .m3u

Songbird will import the file name because that's always the last part, but without a root directory it has no idea where to find that file.

Solution:
Export your m3u from Winamp -> Open it with WordPad -> Add root directory to complete the path -> Save -> Import to Songbird or iTunes

In the example above I just did Find/Replace "\My Music" -> "E:\My Music"

I think you have to be very careful with this Win-amps system of dropping the root directory is if this playlist is copied to a Mp3 player it will have a different root and probably no drive letter.

The good news, once again, is " Rockbox" has already solved this.
Faced with a playlist it crawls along it dropping terms and at each stage comparing it to the file structure on the player, if it finds a match it stops and uses this truncation for the whole playlist. This means usually a Rockboxed Player can play any playlist.

Thanks everyone!