Folder Permissions problem

I asked this question in the Security area and am not getting much help.  Thought I would try reposting it here.

I have the following structure on a server \\Servername\sharename\folder.  Inside of folder I would like to create a structure and have NTFS enforce it so nobody can add edit or delete the file folders. That is to say they should not be able to add their own folders, and they should not be able to do anything to the folders I create under the share. However, They should be able to add edit and delete files.

As to permissions, I have right clicked the folder gone to security and then selected the advanced button.  From here I have the following options for security.

1) Traverse Folder / Execute File  Checked
2) List Folder / Read Data  Checked
3) Read Attributes Checked
4) Read Extended Attributes Checked
5) Create Files / Write Data Checked
6) Create Folders / Append Data UnChecked
7) Write Attributes Checked
8) Write Extended Attributes Checked
9)Delete Sub Folders and Files Unchecked
10) Delete Checked
11) Read Permissions Checked
12)  Change Permissions UnChecked
13) Take Ownership UnChecked
14) Full COntrol Unchecked

This is for the allow entry.  The deny entry is as follows.

Numbers 6, 9 12 and 14 are unchecked.

With these settings I get what I'm looking for on the folder security.  However, If a user edits a file they are not allowed to save it except to a new file name.

It does appear that these setting cause the modify permissions under the basic permissions to be unchecked.  Is there a way of doing this?

Thanks for the help in advance.