I'm trying to edit 1080p video with Final Cut Pro (converted to Pro Res 422), but my MBP can't play it back (in FCP or Quicktime) very well - it's super jerky and out of sync. It's an older model (late 2006) with 2 GB RAM. The max I can go is 3 GB. Will upgrading to 3 gigs do the trick? Thanks!!