[ESS] error message when starting R with M-x R but not from within an emacs bash shell

[RICHARD M. HEIBERGER]

>> options(STERM='iESS', editor='emacsclient')
> Error in options(STERM = "iESS", editor = "emacsclient") :
>   unused argument(s) (STERM = "iESS", editor = "emacsclient")

The "unused arguments" looks to me like you have a naming conflict.
try
   conflicts(detail=TRUE)
I am guessing that your session starts with a saved .RData that has
a locally named function "options".

If you need the .RData file, then remove or rename the offending
function and resave the .RData.
An even better plan is to place those functions into your own package
and then load it.

Rich