Hi there, this is my first posting but I am desperate and need some help Apple could not provide. Here is my situation: - new iMac 9,1 2,93 GHz, 4 GByte, ATI Radeon 4850 - pre-installed OS: Leopard 10.5.6 I have access to a MBP and an older iMac. The MBP had a defective logic board some months ago so I decided to copy its content (after repair) to an external hard drive. I used this hard drive as my primary OS and used it with the MBP or iMac and did have the same data all the time - excellent time-saver for me. Now the new iMac was shipped yesterday. I tried to boot it from the very same external hard drive as well. It worked but there are some annoying facts I need some help to deal with: I cannot activate sleep mode with the new iMac the graphics card seems not to work well: stuttering screen saver, slow high definition video playback, slow spaces etc. I cannot dim the monitor's backlight with F1/F2 keys nor the monitor setup All these problems disappear when I boot from the internal HDD but that is not an option for me. It looks like the "old" Leopard installations lacks of some drivers. Is there a way to add them, is there another solution or will an update of Leopard 10.5.7 - at least most likely - solve the problem? Apple support did not feel the need to help for "exotic configurations". I was told a fresh installation of a retail Leopard copy on an external hard drive COULD work (no guarantee) but it would take me too much time to re-configure and I don't feel the desire to set up my system fresh and new like in old Windows days. So my hope rests in your hands. Any advice is welcome. Thanks for reading this long posting.