Bus error while updating packages

Can anyone suggest what I may be doing wrong?

I had issued the command update.packages(), after which I went through
the usual dialog:

mixtools :
 Version 0.2.0 installed in /Library/Frameworks/R.framework/Resources/
library
 Version 0.3.0 available at http://lib.stat.cmu.edu/R/CRAN
Update (y/N/c)?  y
?
tsDyn :
 Version 0.5-7 installed in /Library/Frameworks/R.framework/Resources/
library
 Version 0.6-0 available at http://lib.stat.cmu.edu/R/CRAN
Update (y/N/c)?  y
trying URL 'http://lib.stat.cmu.edu/R/CRAN/bin/macosx/universal/contrib/2.6/mixtools_0.3.0.tgz'
Content type 'application/x-gzip' length 325712 bytes (318 Kb)
opened URL
==================================================
downloaded 318 Kb
?
trying URL 'http://lib.stat.cmu.edu/R/CRAN/bin/macosx/universal/contrib/2.6/tsDyn_0.6-0.tgz'
Content type 'application/x-gzip' length 519954 bytes (507 Kb)
opened URL
==================================================
downloaded 507 Kb


 *** caught bus error ***
address 0x20, cause 'non-existent physical address'

Traceback:
 1: unlink(instPath, recursive = TRUE)
 2: unpackPkg(foundpkgs[okp, 2], foundpkgs[okp, 1], lib,
installWithVers)
 3: .install.macbinary(pkgs = pkgs, lib = lib, contriburl =
contriburl,     method = method, available = available, destdir =
destdir,     installWithVers = installWithVers, dependencies =
dependencies)
 4: install.packages(update[instlib == l, "Package"], l, contriburl =
contriburl,     method = method, available = available, ..., type =
type)
 5: update.packages()

I am running
R version 2.6.1 (2007-11-26)
i386-apple-darwin8.10.1

locale:
en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base