My son likes video editing, and was using Pinnacle on a PC but our machine was getting past it. Bought one of the new dual core iMacs but son found iMovie a bit limiting. Therefore bought Final Cut Express HD, loaded it, tried to run, and got error message saying that I need an AGP graphics card. Nightmare scenario is that after spending the £1200 or so, this top of the range iMac can't run a cut down version of Final Cut. Say it ain't so?! Can the card be upgraded, or is that not possible with an iMac? Help!!