Exporting is not exporting!

I've been working on a multitrack file in soundtrack pro, that is going to be used later in another program [maybe final cut or after effects]. Anyways I've been working on the project on my own lab top and hard drive, and when I took it to work to move the files to my work computer a lot of my sound effects were missing, I figured it must be because my computer has more sound effects then the one at work. Anyways I instead decided to export the file on my computer into an audio file or mp3 of some kind, but nothing is working.

I go to export, I've tried master mix, i've tried selecting my tracks, and then I pick where I want it to be saved and then click ok or export, but every time I do no new files appear in the folder I designated it to save to, nothing what so ever.

If I could select the four tracks of audio I need and could export them to an mp3 or other working audio file that'd be great Please help!

and incase I sound stupid, this is my first time using STP so I apologize