Making folder with specific permissions

I have a script that creates folders into which it moves files. I’d been using the following successfully:

 make new folder at alias Archive with properties {name:dateString}

I found, however, that this newly created folder was not writeable by a remote user if that user had a different login than the Mac with the folder, even if the remote user had admin privileges. The new folder had read/write privileges for owner, but only read privileges for other (e.g., the remote) admin users.

I didn’t want to give the remote user the local login, so I figured I could modify my folder creation script to allow read/write access by using the following:

 make new folder at alias Archive with properties {name:dateString, group privileges:read write}

I got no error message on using this version, but neither did I get the desired result (admin user with read/write privileges). Instead, I continued to get only read privileges for admin users.

It’ll work if I break this down into two statements:

 make new folder at alias Archive with properties {name:dateString}
 set group privileges of alias Archive to read write

Is this a bug, or am I just not getting the syntax correct in my one-line version?

This has been mentioned at least one before: Change all folder/file permissions; see my post there (#6).

tell application "Finder"
	make new folder at alias spreadsArchive with properties {name:dateString}
	tell result to set group privileges to read write
end tell

Edit: I believe it’s a bug.