[OS X TeX] .tex icons

[George Gratzer]

All of a sudden, all my .tex icons disappeared. All my .tex files, I’m told, will be opened with
TeX.mdimporter. The "Open with” list does not contain TeXShop. If I force it with 
“All Applications” ,  "Open with” changes to TeXShop. Then I click on “Change All…” 
and I’m back where I started.

Also, during this process, the Finder becomes non responsive.

Any way out?

GG