Thunderbird preferred application setting does not stay set after update

[apjjr]

I have to go back to System->Preferences->Preferred Applications and reset Thunderbird as my preferred email program after most updates.

It usually gets set to custom after an update, which does not work right with Firefox alt-F E to send link to email recipient.

I sure would like to know how to make this setting stick.

Thanks,
Alex
Ubuntu 10.04 32bit on Dell Inspiron 1501 - AMD Turion - 2GB ram 80GB HD

[apjjr]

Nobody has a clue? I thought surely I could not be alone with this problem.
Try right clicking a file in Nautilus, then select send to, then set Send AS to Email and click ok. That should open your preferred email program compose dialog with the file as an attachment. This will work with System->Preferences->Preferred Applications set to Thunderbird, but not when it is set to custom, which it gets set to every time I update the system.
Give it a try and let me know what happens on your system.