The following will throw the error \"Error in v$a : $ operator is invalid for atomic vectors\" (at least in R version 2.14.1):
v <- c(a=\'a\',b=\'b\')
v$a
Third paragraph of the Details section of ?"$":
‘$’ is only valid for recursive objects, and is only discussed in the section below on recursive objects. Its use on non-recursive objects was deprecated in R 2.5.0 and removed in R 2.7.0.
R-2.7.0 was released in April, 2008. Four years is far from "recent", but maybe you have been a few versions behind for awhile?