I’ve spent lot of time dealing with it and believe me; it is not trivial at all. Just wanted to share it with you hoping it may help you saving your time.
Standard installation procedure will do it successfully, but you will be missing Xcode.app in Application directory. So, you need to do the following:
• Mount the Xcode 3.2.6 dmg package
• Open Terminal
• Execute the following:
export COMMAND_LINE_INSTALL=1
open “/Volumes/Xcode and iOS SDK/Xcode and iOS SDK.mpkg”
The open command will launch the installer and allow you to install Xcode 3.2.6 on Lion with no package modifications.
That’s it! I hope this may help someone….