[R-Forge #5671] Load, detach and re-load issue with RODBC package

Submitted by: Arun ; Assigned to: Nobody; [R-Forge link](https://r-forge.r-project.org/tracker/index.php?func=detail&aid=5671&group_id=240&atid=975)

As reported [here on SO](http://stackoverflow.com/questions/23498804/load-detach-re-load-anomaly).
