To fix:

• http://docs.mongodb.org/manual/tutorial/recover-data-following-unexpected-shutdown/
• http://docs.mongodb.org/manual/reference/configuration-options/#storage.repairPath (source/includes/options-mongod.yaml)

See the last sentence here:
http://docs.mongodb.org/manual/reference/program/mongod/#cmdoption--repair
and the Note at the bottom of the "Definition" block:
http://docs.mongodb.org/manual/reference/command/repairDatabase/#definition

Basically the --repairpath is only used for storing temporary files while the repair is running. Once finished the --repairpath folder will be empty and the original files in the dbpath will be replaced.

Usually --repairpath is used when somebody is trying to reclaim disk space and it's using another volume with sufficient space to run the repair.