Did you save it as a multiplayer mission? You know the save window the drop down box where you can choose 'export to multiplayer'.
If you first save it as a 'user mission' and then 'export to multiplayer' all the files in the mission folder will be compiled to the one and te same .pbo which can be found under /ofpdir/mpmissions
If you've done all that and you feel like I'm patronizing you (
) then check if you have somewhere in your mission, or the script files a line executing the missing script and remove the line. It should look something like [] exec "*.sqs". After done with it see if it works or not. If it doesn't then I don't know what I'm talking about.