Sweave problem with "$"

[Riccardo Romoli]

Hi, I'm working with Sweave and I suddenly started having a problem  
with "$". I don't know why but now $ is always considered a Math-mode  
character both in ESS-mode than in LaTeX-mod., So, in ESS, every time  
I use $ to select a column the system recognize the wrong mode and I  
can't eval the R code. The problem persist even if I run R CMD Sweave  
from terminal.

Any suggestion??

Best
Riccardo