[ESS] Setting LaTeX mode in Rnw files

[Gorjanc Gregor]

Hello!

I use Emacs (21.3.1) and ESS (5.2.6) for editing Rnw files and I really 
like it. However, sometimes mode assignments fail to follow me. To be more
specific Emacs sometimes fails to change to LaTeX mode, when I swicth
from R code. Therefore, font-locking does not work properly anymore.
It's really not a big deal and I do not know what I do in details that
this happens. Does anybody have an idea? 

Is it possible to assign which mode one wants to use if one finds itself
in a situation like this?

Thank you very much!

Lep pozdrav / With regards,
    Gregor Gorjanc

----------------------------------------------------------------------
University of Ljubljana
Biotechnical Faculty        URI: http://www.bfro.uni-lj.si/MR/ggorjan
Zootechnical Department     mail: gregor.gorjanc <at> bfro.uni-lj.si
Groblje 3                   tel: +386 (0)1 72 17 861
SI-1230 Domzale             fax: +386 (0)1 72 17 888
Slovenia, Europe
----------------------------------------------------------------------
"One must learn by doing the thing; for though you think you know it,
 you have no certainty until you try." Sophocles ~ 450 B.C.