Unable to initdb using HEAD on Windows XP

I just compiled a fresh copy from CVS head. I then tried to do an initdb
as user 'postgres' (non admin user on my system). I get the following error:

C:\Tada\Workspace>initdb -D data
The files belonging to this database system will be owned by user
"postgres".
This user must also own the server process.

The database cluster will be initialized with locale English_United
States.1252.

creating directory data ... ok
creating subdirectories ... initdb: could not create directory
"data/global": Permission denied
initdb: removing data directory "data"
could not open directory "data": No such file or directory
initdb: failed to remove data directory

AFAICS, no data directory is ever created so the 'creating directory
data ... ok' message is probably incorrect. I even tried to change the
permissions on the parent directory so that user 'postgres' has full
control. It doesn't help. I didn't think it would since I am able to
create a database in this directory if I'm using version 8.1.4.

Regards,
Thomas Hallgren