It never ends

Now I have to find a new editing program because my Videostudio X2 will not open the GoPro MPEG4 file even though VS is suppose to support MPEG4. I can open other video files, edit and then output as MPEG4 with no dramas, VS will open these files.
Windows Movie Maker in Vista wont open the GoPro's video either.

I can play the HD GoPro videos in Nero & Quicktime, no drama but not Windows Media Player.

Soooo I need a nice video editing program that will open the HD GoPro files. All I need to do is cut, insert a few transitions a do a title. I know Premier (too costly & pro) will but all I want is something like Videostudio without installing 10 trial programs to find one.

Or a program that will open the file and transcode (?) to a format without loss that Videostudio can open and then edit. Actually if this is possible that would make me happy as I have used Videostudio for years.

Ok long story short, what video editing program do you use to edit HD GoPro video.

Cheers Bob.