I think you meant utils::data 
Anyway, that also suggests that you’ve got something masking data(). If you started a clean session and only loaded the mlbench package, then that should not be the case — mlbench doesn’t have a data() function.
So I’d take a look at your various startup files to see where this might be coming from. It’s not a good idea to have packages (or data frames, via attach()) that you aren’t aware of loading automatically into a clean session (it’s debatable whether it’s ever a good idea at all, but if you’re going to do it you need to be constantly aware of the implications).