Have 8 month old 24in iMac G5. Have what is termed a "garbled video" problem. At any moment a plaid design may cover my entire screen. I can remove it by sweeping the cursor over it for the large area, then using the cursor to sweep the menu items which are also covered. Have taken the computer to Apple Store for repairs. They changed the logic board and the video card, but the problem remains. The store techies tell me that it is a "firmware" problem and is a known issue that they are working on. It has been about two months since I first had the problem and took the computer in. How long does it usually take for the Apple engineers to create a fix for a problem such as this? Has anyone else had a similar problem? Has anything worked to correct it?