R help - Mar 2008 - Vista#package installation#difference between Rgui and Rterm#Help me understand

Hi all,

Found some comments on this on the FAQ under 2.24 but someone may have 
some more explanations ... and I might then understand.

Operating system: Vista Ultimate (SP1 test version)
Installed R: R version 2.6.2 (2008-02-08)

When I try to install packages which need to write into privileged 
spaces, I am inclined to run the RGui "As an Administrator".  I would 
then want to use the pull down menu to set the download side and to 
select the desired package. However, this gives me "could not copy files 
from temporary ..." messages. This suggests that the administrator 
privilege got lost on the way.
Running install.packages("...") in the Rgui seems to work better. Then
again, it only works partly. One of the packages I wanted to install is 
an experimental version of the RExcel.installer. Somewhere down the 
road, this installer invokes rcom and makes an entry in the registry. 
For this it needs administrator privilege and seems to have lost it by 
then.

On the other hand, when I run R in a CMD shell started "As an 
Administrator"  then everything works as expected.

Why is this so?

Thanks in advance,

Chris.