How to Reininstall Xcode on Snow Leopard?

I am (mostly happy) Mac OS X 10.6 aka Snow Leopard user. Several days ago I've decided to reinstall Xcode 4.0.1 because the AppStore shows me that the update is available but updating has failed every time with message "You have updates available for other accounts. Bla-bla-bla" (It was my first "Sorry, what?"). Of course, my account is correct and couldn't be "other": I use only one account for a year both for iPad and MacOS. So from my Windows experience I've decided that reinstalling of Xcode will give me the update and solves the problem with "other" account.

The second "Sorry, what?" was when I can't find the "Uninstall" button in AppStore. OK, thanks Google, I got the receipt:
sudo /Developer/Library/uninstall-devtools --mode=all

The program has done its work and I go to AppStore and find that Xcode is still installed. WTF!? I reboot the MacBook but nothing changed. OMG! Let's continue.

Google is my friend. There are a lot of people with the same problem. And so many solutions. One worked for me:

• sudo rm /var/db/receipts/*Xcode*
• Remove /Applications/Install Xcode.app completely (Zip it for backup purposes, because due to periodical AppStore problems it can became impossible to download Xcode) and remove the original).
• Restart the AppStore.

After this I can successfully install the newest Xcode.

UPDATE: Apple team had fixed the problem very well. I've updated Xcode 2 or 3 times more and get no one problem with it. Thank you guys!