Gnome looses all mime-types bindings, how to fix ?

[Vladimir Grebenschikov]

Hi

After some changes (probably upgrade) gnome looses mime-types bindings,
as results:

- nautilus does not suggest appropriate application to open icons
- nautilus does preview with wrong type (like text preview for gnumeric
sheets)
- evolution does not preview inline text and patch attachments
- evolution does not opens appropriate viewer for attachments
- etc

how to find solution for problem ? what to check or how to reinitialize
mime types db.

Thanks for answers.

-- 
Vladimir B. Grebenschikov
vova at fbsd.ru