Keychain says "Access to this item is restricted" after upgrading to Lion I recently upgraded to Lion and since then I haven't been able to use Keychain to look at my stored passwords.  When I click on the checkbox to show them it prompts me for my master password, then pops up a dialog that says "Access to this item is restricted".

Based on reading questions here and on other support sites, I've tried using the Keychain Access program's "Keychain First Aid" feature.  It reports that there are no errors.  I also used Disk Utility to Repair Disk Permissions, and this didn't fix the problem either.

I looked in ~/Library/Keychains/ and it looks like I do have owner permission to read and write the keychain file, and my main account is the owner.

Is there anything else I can try to fix this?  I'd hate to lose my keychain passwords.

Update:

I also tried dragging my login.keychain file from Finder into Keychain Access, and had no luck.  I tried some digging around in the security command line app as well, but have made no progress...

Update 2:

After trying all the suggestions I commented on here I was still getting this error, but then I did a software update, and rebooted, and now my keychain is working again.  So, I have no idea what went wrong, but it is now fixed!  I'll just pick an answer as accepted.
Does running the command-line version of Keychain:

security dump-keychain -d login.keychain


also fail, but with the weird message In dark wake, no UI possible?

Then part of Mac OS is confused about whether it is asleep or not. There’s no need to reboot. Put it to sleep, wake it up, and Keychain should be fine again. This happens on my MacBook Pro sometimes: I open it to wake it, press the power button out of habit, only to turn it off as it is trying to start up, resulting in weird Keychain behaviour.