I\'m playing with meteor, Installed it on Ubuntu 14.10 & followed the todos tutorial. The Meteor run log:
$ meteor run [[[[[ ~/bckd/homedir/learn/meteor/
check if there is a running mongo process, and kill it manually:
ps -aux | grep mongo sudo kill [pid]
..then restart your meteor app.
--> I think this specific situation exists only when starting meteor on a custom port (not tested, but pretty obvious)