folks, I got a really serious problem after the 10.4.8 update: My MacBook is now in an unbootable state. I restarted the computer after the update, and instead of booting into MacOS from EFI I had vertical stripes in all colors. Well, I did a reset of SMC, NVRAM and stuff and now the grey EFI screen is showing me a blinking grey folder with a question mark!!! Holding the ALT key shows me my harddisk, but a few seconds after that the question mark folder blinks again. Is there anything I can do myself to fix it? thx!