can set readonly attribute but not clear it ?!?

[Frank van Maarseveen]

server: Linux + samba-2.0.6, security=USER
client: NT4SP4

Enabling the readonly file attribute on a file I own succeeds from
NT. However, disabling the attribute again fails. According to the log
file smbd tries to open the file in read-write mode though I'm only
changing its attributes. The opening fails of course (confirmed by
strace).

Another samba server with security=SERVER doesn't seem to have this
problem.

Is there a patch or any other solution for this problem?

-- 
Frank