Problem with creating default NAMESPACE on FreeBSD

After building and installing R-devel from 21/07/2011 on FreeBSD 9.0-CURRENT 
(amd64), starting R gives the following warning:

[..snip..]
Beim Start - Warnmeldung:
package 'datasets' in options("defaultPackages") was not found

This happens with all versions after 14/07/2011. I think it is related to

NEWS Sat, 16 Jul 2011
CHANGES IN R-devel PACKAGE INSTALLATION
Packages without explicit ?NAMESPACE? files will have a default one created 
at build or INSTALL time, so all packages will have namespaces. A consequence 
of this is that ?.First.lib? functions need to be renamed, usually as 
?.onLoad? but sometimes as ?.onAttach?.


Package 'datasets' seems to be installed correctly under 
/usr/local/lib/R/library/:

ls -l datasets/
total 18
-rw-r--r--  1 root  wheel  -  289 22 Jul 08:12:04 2011 DESCRIPTION
-rw-r--r--  1 root  wheel  - 5547 22 Jul 08:12:04 2011 INDEX
drwxr-xr-x  2 root  wheel  -  512 22 Jul 08:12:04 2011 Meta
drwxr-xr-x  2 root  wheel  -  512 22 Jul 08:12:04 2011 R
drwxr-xr-x  2 root  wheel  -  512 22 Jul 08:12:04 2011 data
drwxr-xr-x  2 root  wheel  -  512 22 Jul 08:12:04 2011 help
drwxr-xr-x  2 root  wheel  -  512 22 Jul 08:12:04 2011 html


Calling options("defaultPackages") shows all relevant packages:

$defaultPackages
[1] "datasets"  "utils"     "grDevices" "graphics"  "stats"     "methods"


But trying to load library 'datasets' fails with the following message:

library(datasets)
Fehler in library(datasets) :
 package 'datasets' does not have a NAMESPACE and should be re-installed


Googling around for some days now it looks like this does not happen to 
anyone else (at least there are no infos). Does anybody knows what is going 
on here?

Any help would be appreciated,
Rainer Hurling



sessionInfo()
R Under development (unstable) (2011-07-21 r56467)
Platform: amd64-portbld-freebsd9.0 (64-bit)

locale:
[1] 
de_DE.ISO8859-15/de_DE.ISO8859-15/de_DE.ISO8859-15/C/de_DE.ISO8859-15/de_DE.ISO8859-15

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