Replying to Editing 1080 30p h264 on Windows

I am trying to edit video that I shot on my Iphone in Premiere CS4 on Windows 7.

My computer has no problem playing the files that I imported.

When I import the files into Premiere, the computer lags, it is almost impossible to preview the files in Premiere and impossible to scrub through the files.
I can cut the the clips on my timeline and export the file which my computer has no problems playing.

I updated my h264 codec and experienced the same issues in Premiere.

I tried converting the videos to Cineform with the Gopro Studio App that I downloaded. I still can't edit in Premiere.

Does anyone have any advice on editing files like this? I really want to edit some of this footage and I am not afraid to try new software.

I am not biased to CS4, I use it because I prefer it over Sony Vegas and I torrented the CS4 pack a few years ago.

My computer should be fast enough to handle this. I am running Windows 7 Professional, I have 8 gb of ram, and a 2 ghz processor.


Does anyone have any similar experience or advice?


Thanks