Brand new iMac, Aperture installed from Mac AppStore crashes on startup

Question

I installed Aperture 3.0 from the Mac AppStore yesterday, but it crashes immediately on running, with this message:
Dyld Error Message:
Library not loaded: /Library/Frameworks/PluginManager.framework/Versions/B/PluginManager
Referenced from: /Applications/Aperture.app/Contents/MacOS/Aperture
Reason: no suitable image found. Did find:
/Library/Frameworks/PluginManager.framework/Versions/B/PluginManager: no matching architecture in universal wrapper
I bought my iMac a few days ago. There's a few apps installed, including Final Cut Express 4.0 - installed from CD - which given all the other threads I've read with the same crashing message, may make a difference.
I used the Aperture troubleshooting basics (http://support.apple.com/kb/HT3805) - let me explain each step.
- I just bought my iMac, brand new last weekend, if it doesn't meet system requirements I'll eat my hat
- It wasn't the first thing I tried, but I have since run a "Software Update" which included updates for both Final Cut Express and Aperture... after they installed, I rebooted and Aperture still crashes on startup with the same message
- The Aperture first-aid-tools are irrelevant I'm afraid. If I didn't know any better, I'd say they didn't work at all - as holding Option/Command while starting Aperture makes no difference... but I suspect the crash happens before the tools get a chance to run
- Time Machine backups would also be irrelevant since this is a fresh install (what does "Restore the Library" mean anyway - what library?)
- Restoring Aperture back to its original settings is irrelevant since I haven't changed any
- I tried reinstalling Aperture, exactly as described. I deleted Aperture from Applications, went to the Mac AppStore and redownloaded it; rebooted; it still crashes in the same way
Here's more of the message below... and yes, as you can see, I've tried more than 50 times ;-(
If I have to reinstall the OS, I might just as well get a refund. I'd love to solve this, but I seriously hope reinstalling the OS is not required.
I just spent 3 days solving an issue where I couldn't download any apps from the AppStore at all, so please let me sell an iMac to my mother without explaining how long it takes to download 1 app and get it running on a brand new machine !
Interval Since Last Report: 218019 sec
Crashes Since Last Report: 51
Per-App Crashes Since Last Report: 47
Anonymous UUID: E1A91A1E-F665-4A88-8101-7D4D60A61D89
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000
Crashed Thread: 0
Dyld Error Message:
Library not loaded: /Library/Frameworks/PluginManager.framework/Versions/B/PluginManager
Referenced from: /Applications/Aperture.app/Contents/MacOS/Aperture
Reason: no suitable image found. Did find:
/Library/Frameworks/PluginManager.framework/Versions/B/PluginManager: no matching architecture in universal wrapper
Binary Images:
0x7fff5fc00000 - 0x7fff5fc3bdef dyld 132.1 (???) <486E6C61-1197-CC7C-2197-82CE505102D7> /usr/lib/dyld

Answer 1

I believe the second half of the solution addresses what you are experiencing. You don't have to re-install the OS, just try the 10.6.6 combo update:
http://support.apple.com/kb/TS3528