[evoLver]

Hello

Suddenly my downloads are all being named "securedownload" (actually it might just be those downloaded through Yahoo Mail).

And, most of them PDF's, they do not open. the error message says "ColorSync Utility cannot open files of this type".

[zro]

My guess would be that you don't have the Finder set to always show file extensions and that these downloaded files don't have a .pdf (or whatever) extension. Check that in the Finder's preferences, add the extension if it's missing from the files and try to open them again.

If they do have the proper extension, have you tried dropping them onto your favorite PDF (or whatever) viewer? If that works, you can set which app they open with using the Finder's Get Info window.

If that doesn't work, well, sounds like it's Yahoo that's causing your problem.