I installed the Security Update 2006-003 last night on my Intel Mac mini. On restart the screen is showing the grey Apple logo for several seconds, followed by the "Starting Mac OS X" banner and then the login box flashes up briefly and disappears leaving a blue screen with the spinner. After a few seconds, it drops to the single-user login (black screen with username prompt in top-left corner). Entering unix-commands is possible, but no graphic interface is coming up. It isn't possible to get to the GUI safe mode (same thing happens). I've tried resetting the flash using Cmd-Opt-P-R. I've also tried an fsck of the disk and repairing system permissions by booting off the installer CD (Cmd-C) and using disk utility to repair permissions. I've removed startup items from /Library/StartupItems but guess that I still have per-user PPC startup items configured. In any case, I am not sure this is the same issue as the StartupItems issue reported elsewhere in these forums as there are reports of the same symptoms but with a PPC Mac on the Apple support site. Any suggestions?