can't edit files in my public guest allow rw folder

Precise 3D 32-Bit up-to-date

What you expected to happen:
When right clicking a folder and selecting these sharing options:
* Share this folder
* Allow others to create and delete...
* Guest access
+ Modify Share
+ Adding the needed permissions by conforming that option in the upcoming dialog

it should be possible to copy any file from an other computer through the network to mine. The received files should be accessible to me as any other file in my home directory.

What happened instead:
I was able to see, mount and send a couple of images from my laptop to my precise machine. Then I tried to edit an image in my shared local folder. This wasn't possible → 'permission denied' error.

Rights of all received files inside the share:
-rwxr--r-- 1 nobody nogroup

When removing the folder from samba by unchecking the 'Share this folder' box and clicking the approval button the files inside the folder belong still to 'nobody' and 'nogroup'.

This is a show stopper, no average user would know what to do, my parents would be lost.

Suggestion:
Change file during this kind of open world samba share (everybody has rw access) to $USER:nogroup. When removing the share, the permissions should be changed to $User:$User.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: samba 2:3.6.3-1ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-17.27-generic-pae 3.2.6
Uname: Linux 3.2.0-17-generic-pae i686
ApportVersion: 1.94-0ubuntu1
Architecture: i386
Date: Fri Mar 2 20:53:34 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta i386 (20120227)
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: samba
UpgradeStatus: No upgrade log present (probably fresh install)