My 15 MacBook Pro C2D 2.33GHz seems to have an issue with burning DVDs at anything higher than 2x. I'm using Toast 7. When I try to burn a DVD-Video disc (UDF) to play in a normal DVD player, and set it to the highest speed that it can go at (usually it's either 6x or 4x depending on the disc), the timer would go down very slowly. When it gets near the mid-way point, it starts burning faster and the timer goes down in real time. Usually, the disc has a problem and either plays only for a short while, or doesn't play at all (in a DVD player or on the Mac). The Apple store genius guy said it was probably a media problem, but I doubt it's a media problem because it does it with both Memorex and Maxell DVDs. I haven't used another brand yet, but it would most likely be the same. I had a similar problem with my G3 iMac with USB 1.1 and an external CD Burner. USB 1 was too slow to support anything over 4x burning. So if I were to set it to 6x, or 24x, or whatever, the timer would go down very slowly and usually render the disc unusable. Could it be a similar problem? I just have the standard 5200RPM HD, but it can't be that slow as to not be able to support 6x (or even 4x) DVD burning, can it?