[Samba] Strange directory creation behaviour

[Edward Strong]

Greetings,

I'm having a really hard time getting this to work the way I want it to.
I have a Samba file server (3.0.25b-2) on Fedora 7 which serves around 20
clients (mostly WinXP but a couple of Macs).  They all login via a single
shared samba user which has full read/write permissions for the entire
served directory.  Unfortunately, I have two major problems:

1.) On an XP client, when copying a directory over to the server via
Explorer, it is created with the read-only flag set.  My immediate
assumption was a permissions problem, BUT if I use XCOPY via the command
prompt, then directories copy across fine.  This is not an acceptable
solution, however, since the average end-user doesn't even know what a
command prompt is!

If I manually create a folder on the server via Explorer (right click ->
new folder) then it will be created WITHOUT the read-only flag set, so why
this is only happening when copying pre-created directories is really
beyond me :(

2.) More directory creation woe with Mac users.  When they create a
directory on the server via Finder, it doesn't create properly.  If you
refresh the folder it appears, but if you try to click on it so you can
open it, then it just disappears.  Refreshing again will make it
re-appear, but you can never get in to it.  They can use any pre-existing
folders no problem, however.

I do not purport to be a Samba expert, so if there's something obvious
that I'm missing here I apologise in advance.

Thank you for assistance,

Edward