[R] R CMD check

[Jeff Breiwick]

Dear R-Group,

I have a function that sorts a data frame and oneo of the lines in the 
function is:

vars <- unlist(strsplit(formc, "[\\+\\-]"))

The function works fine and the above line is always reached. However, when I 
include the function in a package and run "R CMD check pkgname" it gives this 
error message:

'\+' is an unrecognized escape in character string starting "[\+"
Execution halted

I am running Win 7, R-2.13.1 and run R CMD ... from a command line, using 
shell ("start cmd").

I didn't write the function but it has always run fine without any errors.

Is there a way to resolve this so it will pass the package check?
Thank you.

Jeff