Hi Gary, Also runs smoothly on my machine, timeline and produced.
1. Did you update your video drivers? This is really important and as I said solves many editing problems.
2. Something I did notice is you shot your video using "Interlaced" option. Interlaced is an old carry over from analogue TV's. Without getting all complicated you are better off shooting in "Progressive" mode.
Interlaced records half a frame at a time then combines them when processing. Progressive records a single frame at a time so no added overhead when editing or playing back.
3. As Tony suggested try recording at 17mbps plus progressive instead of interlaced to see if that gives your computer an easier time.
Editing video is about the hardest thing you can ask your computer to do, especially editing full blu-ray quality 1920X1080 24mbps as your video is.
Before I upgraded my machine I had to shoot at 1280X720 to guarantee my machine could edit my videos easily.
Let us know how you go and believe me there are sooo many people out there who buy their new HD video camera and find out their computer is not powerful enough to edit full HD video. Drop the recorded quality a bit and if that solves your problem.
Cheers
Robert2 S
My youtube channel====> http://www.youtube.com/user/relate2?feature=mhsn