Description of problem:
After Set the last *number* of messages in the Edit->Account Settings->Offline & Disk Space,the folder properties still keep the default setting

Version-Release number of selected component (if applicable):
thunderbird-1.5.0.12-18.el4 

How reproducible:
Always

Steps to Reproduce:
1.Go to Edit->Account Settings->Offline & Disk Space
2. check option "Delete all old messages but the last *number* messages", set $NUMBER to 1.
3.click "OK"
4.choose any folder of this account, go to Edit->Folder Properties, in Tab "Retention Policy"
  
Actual results:
In the Folder Properties the "Retention Policy" the checked option is still the default one "Don't delete any messages"

Expected results:
option "Delete all  but the last 2 messages" is checked in the Folder Properties the "Retention Policy"

Additional info:
in fedora 9 there is also the problem thunderbird-2.0.0.14-1.fc9