Hi
Compressor can be a troublesome programme. Its not your mac. It should never be taking this long for a 5min film.
I would cancel your queue in batch monitor. If this doesnt work, (which if there is a problem with compressor it sometimes doesnt), then in compressor menu select reset and cancel background processing.
Are you using qmaster to using all of your machines cores? If not then you should as it will speed up your batch. There are loads of tutorials explaining how to do this. its very easy. If you are using it already, then it can be temperamental, so again i would cancel it. And in the qmaster preference sin system preferences i would "stop sharing" and then restart sharing.
Are you exporting as a quicktime and then putting into compressor? I would recommend this rather than doing it from the timeline. It frees up FCP so you can carry on editing, or if nothing else it enables you to close FCP which will help speed up compressor.
Compressor sometimes copies the film to your system drive, and if you ware running out of space then it will slow to a crawl.
You can also try various compressor fixing software, which basically cleans it out and enables you to start again. This one is recommended.
http://www.digitalrebellion.com/compressorrepair/
cheers
nick