There is a problem with shares where any client cannot have write access. The 
problem began sinces 3.0.3 (including 3.0.4) because with 3.0.2a, works 
perfectly, even using the same configuration.

I have made some test, and I found that the problem is about the conflict 
between the read only directive, write list and read list. The results of my 
some tests that I did:

1) read only on, user in write list: Write access denied!
2) read only off, user in write list: Write access ok
3) read only off, user in read list and not in write list: Write access ok!

It seems that the read only directive is taken after procesing the write and 
read list. That because, if the read only is off and user is in read list, the 
user can write and the inverse is also true.

The tests was made using smbclient under linux 2.2 x86 and using a Windows XP