Mac Mail keeps rearranging the columns that I have set to view.

I like to have the "attachments" column on the left side so I can see at a glance whether someone has sent something. And I make the columns more useful widths. It holds the settings for a few days, but then I come back and it has set them all back to the factory default, and I have to re-set them.

Is there an option somewhere to make my settings choices "stick"? Is it a bug that they fix in a later version?

I'm running Mail 2.1.3 on OSX 10.4.11 on a MacBook Pro.