PLS & M3U files are written with file URLs rather than paths, which confuses some other software, 
including musicmatch.

This fixes it:

Index: Slim/Formats/Parse.pm
===============================================================
====
RCS file: /home/cvs/cvsroot/slim/server/Slim/Formats/Parse.pm,v
retrieving revision 1.20
diff -r1.20 Parse.pm
319,320c319,320
< 
<               print $output "File$itemnum=$item\n";
---
>               my $path = Slim::Music::Info::isFileURL($item) ? Slim::Utils::Misc::pathFromFileURL($item) : 
$item;
>               print $output "File$itemnum=$path\n";
375,376c375,376
< 
<               print $output "$item\n";
---
>               my $path = Slim::Music::Info::isFileURL($item) ? Slim::Utils::Misc::pathFromFileURL($item) : 
$item;
>               print $output "$path\n";