Rd.sty error

I had written a vignette and included a
\usepackage{Rd} command to make it possible to include
latex'ed Rd files in the vignette. However, when loading
Rd.sty texShop produces the following error:

l. 180 ...d}[1]{\ifmmode\bm{#1}\else\textbf{#1}\fi}

This is on Max OS X 3.9 and R 2.0.1

Has anyone seen this before and/or is it problematic? I'm not sure whether
the output suffers from this but it does create a problem with R CMD check
because tex produces a warning/error there.

any hints are welcome, ingmar

Ingmar Visser
Department of Psychology, University of Amsterdam
Roetersstraat 15, 1018 WB Amsterdam
The Netherlands
http://users.fmg.uva.nl/ivisser/
tel: +31-20-5256735