Valgrind on Snow Leopard or Lion

I have been tying to get valgrind to run on Snow Leopard and Lion 
without much success. I get reports of errors but the process tends to 
hang before exiting. It only terminates occasionally after an error. 
Thus I cannot get leak reports.

For example: if ls.r contains the one line: ls()

R -d "valgrind --tool=memcheck" --no-save < ls.r

will produce the following and hang

==32176== Memcheck, a memory error detector
==32176== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==32176== Using Valgrind-3.8.0.SVN and LibVEX; rerun with -h for 
copyright info
==32176== Command: 
/Library/Frameworks/R.framework/Resources/bin/exec/x86_64/R --vanilla
==32176==
==32176== Warning: ignored attempt to set SIGUSR2 handler in sigaction();
==32176==          the SIGUSR2 signal is used internally by Valgrind

R version 2.14.0 (2011-10-31)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)

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