Just upgraded to Tiger, now at 10.4.11... and my new iMovie 08, also just installed (previously had iMovie HD, from iLife 05) won't open at ALL. I've researched & see no real clear answer in any forums here or elsewhere, aside from one idea to Recalibrate the Monitor (!!). For the record, I have all the specs: Apple specs minimums are OS 10.4.9, a G5 PowerPC dual 2.0GHz or better (I have that), I GB of memory (have 2.5); need 3 GB of space, have 78 GB. I've also done all updating available. So? Should I try to delete and reinstall iMovie only?