Hi. I'm a long time user of hackintosh (but on an intel platform using mostly vanilla files) and from some time a happy macbook user.
Recently, by accident, I noticed that all my shared files via AFP and SMB are writeable for guests. I have everything set properly in sharing preferences (only my user 'widget' has read and write access, all others have read only access). You can see that in following smbstatus dump:

CODE
wgt:~ widget$ smbstatus

Samba version 3.0.25b-apple
PID     Username      Group         Machine                        
-------------------------------------------------------------------

Service      pid     machine       Connected at
-------------------------------------------------------
IPC{:content:}nbsp;        1386   kasia         Thu Jul 24 15:21:41 2008
apps win32   1386   kasia         Thu Jul 24 15:21:43 2008

Locked files:
Pid          Uid        DenyMode   Access      R/W        Oplock           SharePath   Name   Time
--------------------------------------------------------------------------------------------------
1386         4294967294  DENY_NONE  0x20189     RDONLY     EXCLUSIVE+BATCH  /Volumes/Dane/Apps Win32   driver_raid_promise_20276.exe   Thu Jul 24 15:22:01 2008
1386         4294967294  DENY_NONE  0x100001    RDONLY     NONE             /Volumes/Dane/Apps Win32   .   Thu Jul 24 15:21:44 2008


It is RDONLY, but I can freely delete files from remote computers on my LAN. I even tried connecting via AFP (also as guest) and I could delete files.
I don't know what to do. Anyone has any suggestions?