I have a drive mounted on a Windows 7 64-bit machine from a VirtualBox Ubuntu VM via NFS. Whenever I try creating a folder from Windows, the folder is created with its executable bit set to false, rendering it non-navigable and non-writable unless I switch to Ubuntu and manually reset folder permissions.
This bars me from creating folders or using any version control software from Windows. Is there any way to enable setting x permissions on folders creating via NFS?
EDIT: adding info as suggested by jdebp:
I'm using the MS Services for Unix client to map the NFS drive to G:. The output of the nfsadmin client command on the client (thus forth known as my host Windows 7 machine) is:
Service 'NfsClnt' was not found.
I have the server set up on Ubuntu to treat anonymous mounts as uid=1000 and gid=1000 (my Ubuntu user's uid and gid) and the client is configured to have executable flags set in its umask.
When I create a file on the mounted share (either through Eclipse or from Windows Explorer, for instance), the permissions are correctly set:
-rw-rw-r-- 1 klemen klemen 0 2011-07-05 09:46 test.txt
But when I create a directory (either from Eclipse, Windows Explorer or from the command line using mkdir), the directory is created without its executable flags:
drw-rw-r-- 2 klemen klemen 4096 2011-07-05 09:42 test
My mount options are as follows:

nfsadmin clienton your client machine, and tell us what tool you are using (The POSIXmkdircommand? The Win32mdcommand? Explorer?) to create the directory. – JdeBP Jul 4 '11 at 17:08ext4. – KrofDrakula Jul 12 '11 at 8:32