I am referring to my problem description posted in this thread and was adviced to post part of my problem here to get the attention of the OSX experts who might know how the updates are delivered. My problem is that my new iMac (2,93 GHz 4 GByte RAM, ATI Radeon 4850) is supposed to work with an older installation of Leopard (10.5.6, MBP dump, no retail, all updates included). Reason: I want to use an external drive with all applications and documents on different Macs. It worked on the MBP and an older iMac perfectly. Unfortunately, the hardware of the new iMac is not perfectly supported by my "older" Leopard OS yet. Sleep does not work, dimming of backlight does not work and the graphics card is stuttering (screen saver, HD video etc.). It looks like there are some drivers missing. How can I ensure the upcoming Leopard 10.5.7 update to deliver the missing drivers? Will it deliver new drivers at all? Can I influence the update process? Or do I have to expect it to deliver the MBP update files (only) even when I connect the hard drive with my iMac? I have no clue how updates work. Until today, I hit the update button and was fine. If it can help sorting things out, I add the recent Leopard build numbers for both my MBP Leopard and my iMac Leopard installation, both with all available updates, fixes etc. installed: - Leopard 10.5.6, Build 9G55 ("old" Leopard = MBP OEM dump with problems) - Leopard 10.5.6, Build 9G3610 ("new" iMac pre-installed OS working ok) Thanks for your comments and thoughts!