Dear all, I did not find anything related to this problem; Samba with sendfile support enabled, works fine with W2k but not with NT4. Problems with NT4 are constant lockups (which take half a minute for computer to start responding again) when accessing network drives. - All our NT4 workstations show this behaviour. - Disabling sendfile cures this problem. - W2k workstations are not affected in any case. Anything to test? Is this a known reason? Regards, Jarmo