Can't activate Guest Account: System freeze

[Trinity]

New Mac Mini 2009, Apps, user and settings imported from a G4 Cube running Leopard perfectly. When I go to System Prefs - Accounts - Guest and I mark the checkbox "Allow Guests connect to this computer" System Prefs freezes with rainbow pizza. Then, no matter if I kill the application or not, the system is death. If I launch new apps from the dock, they bounce a four five times and then stop but the applications don't launch. Not even I can restart. When all the applications closes the system starts a loop of spinning clock wheel - blue screen - clock wheel - blue screen forever.
This is the second new Mac that has the same exact problem after importing all my data, and it's 100% reproducible. I returned the first one to Apple cause I thought it was a hardware failure. What I have done?
Repair permissions and diks
Reinstall the system
Create a test user and try from there
Try from root user
System log when I click the guest box:
System log after checking Guest User Access:

Mar 20 17:48:40 Mini ReportCrash182: Formulating crash report for process securityd23
Mar 20 17:48:40 Mini com.apple.launchd[1] (com.apple.SecurityServer23): Stray process with PGID equal to this dead job: PID 179 PPID 1 SecurityAgent
Mar 20 17:48:40 Mini com.apple.launchd[1] (com.apple.SecurityServer23): Stray process with PGID equal to this dead job: PID 178 PPID 1 authorizationhos
Mar 20 17:48:40 Mini com.apple.launchd[1] (com.apple.SecurityServer23): Exited abnormally: Segmentation fault
Mar 20 17:48:40 Mini ReportCrash182: Saved crashreport to /Library/Logs/CrashReporter/securityd_2009-03-20-174840_Mini.crash using uid: 0 gid: 0, euid: 0 egid: 0
Mar 20 17:49:41 Mini /Applications/TextEdit.app/Contents/MacOS/TextEdit171: SessionGetInfo(0xffffffff) -> Mach 268435459
Mar 20 17:49:41 Mini /Applications/TextEdit.app/Contents/MacOS/TextEdit171: CSBackToMyMac::_SCSecKeychainCopySystemKeychain returned NULL
Mar 20 17:49:49 Mini /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd190: SessionGetInfo(0xffffffff) -> Mach 1102
Mar 20 17:49:49 Mini /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd190: GetOurLSSessionIDInit(), returned error 0xe2, securitySessionID=0x0 attrs=0 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:49 Mini /System/Library/CoreServices/coreservicesd62: Client must provide a valid sessionID but passed 0, 0x0/0x0 version=10500000 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:49 Mini /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd190: LaunchServices/5123589: coreservicesd is running an unsupported version, 0 ( we are 10500000 ), so we cannot talk to it.
Mar 20 17:49:49 Mini /System/Library/CoreServices/coreservicesd62: Client must provide a valid sessionID but passed 0, 0x0/0x0 version=10500000 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:49 Mini /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd190: LaunchServices/5123589: coreservicesd is running an unsupported version, 0 ( we are 10500000 ), so we cannot talk to it.
Mar 20 17:49:53 Mini /System/Library/CoreServices/ReportCrash191: SessionGetInfo(0xffffffff) -> Mach 1102
Mar 20 17:49:53 Mini /System/Library/CoreServices/ReportCrash191: GetOurLSSessionIDInit(), returned error 0xe2, securitySessionID=0x0 attrs=0 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:53 Mini /System/Library/CoreServices/coreservicesd62: Client must provide a valid sessionID but passed 0, 0x0/0x0 version=10500000 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:53 Mini /System/Library/CoreServices/ReportCrash191: LaunchServices/5123589: coreservicesd is running an unsupported version, 0 ( we are 10500000 ), so we cannot talk to it.
Mar 20 17:49:53 Mini /System/Library/CoreServices/ReportCrash194: SessionGetInfo(0xffffffff) -> Mach 1102
Mar 20 17:49:53 Mini /System/Library/CoreServices/ReportCrash194: GetOurLSSessionIDInit(), returned error 0xe2, securitySessionID=0x0 attrs=0 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:53 Mini /System/Library/CoreServices/coreservicesd62: Client must provide a valid sessionID but passed 0, 0x0/0x0 version=10500000 uid=502 euid=502. cf Radar 5123589.
Mar 20 17:49:53 Mini /System/Library/CoreServices/ReportCrash194: LaunchServices/5123589: coreservicesd is running an unsupported version, 0 ( we are 10500000 ), so we cannot talk to it.
Mar 20 17:49:53 Mini com.apple.launchd108: catch_mach_exception_raise_state_identity(): thread: 0xa8cf task: 0x8eaf type: 0xa code: 0x2c044 codeCnt: 0x2 flavor: 0x2c054 old_state: 0x2c05c old_stateCnt: 0x2c new_state: 0x2b02c new_stateCnt: 0x2b028
Mar 20 17:49:53 Mini com.apple.launchd108 (com.apple.ReportCrash.SafetyNet194): Exited abnormally: Abort trap
Mar 20 17:49:54 Mini ReportCrash195: Formulating crash report for process ReportCrash191
Mar 20 17:49:54 Mini ReportCrash195: Saved crashreport to /Library/Logs/CrashReporter/ReportCrash_2009-03-20-174953_Mini.crash using uid: 0 gid: 0, euid: 0 egid: 0
Mar 20 17:49:54 Mini com.apple.launchd108 (com.apple.ReportCrash191): Exited abnormally: Abort trap
Mar 20 17:49:55 Mini ReportCrash195: Formulating crash report for process quicklookd190
Mar 20 17:49:56 Mini ReportCrash195: Saved crashreport to /Library/Logs/CrashReporter/quicklookd_2009-03-20-174954_Mini.crash using uid: 0 gid: 0, euid: 0 egid: 0
Mar 20 17:49:55 Mini com.apple.launchd108 (com.apple.quicklook190): Exited abnormally: Abort trap
Mar 20 17:49:55 Mini com.apple.launchd108 (com.apple.quicklook): Throttling respawn: Will start in 5 seconds

Help!

 

[JediMeister]

Running migration during setup assistant from a PPC to Intel computer leads to bad things. You may have been better off running migration after the system was set up and a user account created. In all likelihood you'll want to erase & install the mac mini, go through the setup assistant, THEN migrate.