Description of problem:
In thunderbird,select a message with attachment then delete it,witness it doesn't work

Version-Release number of selected component (if applicable):
every version,from 1.5.0.12-17.el4 to 2.0.0.16.f9

How reproducible:
always

Steps to Reproduce:
1.Launch thunderbird,select a message with attachment
2.Click the attachment then right click the mouse to delete the attachment

  
Actual results:
Witness the attachment can't be deleted

Expected results:
Attachment should be deleted

Additional info: