Cannot install Xcode4 on very new MacBook Pro with Lion 10.7.2

Question

Hello,
I am trying to install Oracle DB 10g on my brand new Mac OS X 10.7.2 Lion Mac Book Pro.
One of the Oracle requirements is to have either the:
A) Dec 2003 gccLongBranchTools update installed; or
B) install XCode Tools 1.2 or higher, which includes the correct version of gcc
Well, when I try to install XCode 4 with Mac OS X and iOS SDK's I got 2 errors:
1. an error regarding permissions on sudoers which appears to have been fixed by running Disk Utility - Repair Permissions - at least it's not appearing in the install.log file at this time
2. and the other which is more of a mystery to me, it reads
PackageKit: Install Failed: Error Domain=PKInstallErrorDomain Code=110 "An error occurred while extracting files from the package “iPhoneSDK5_0.pkg”." UserInfo=0x7fdf8a4d2190 {NSLocalizedDescription=An error occurred while extracting files from the package “iPhoneSDK5_0.pkg”., NSFilePath=/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/Cleanup At Startup/PKInstallSandbox-tmp/Root, NSURL=file://localhost/Applications/Install%20Xcode.app/Contents/Resources/Pack ages/iPhoneSDK5_0.pkg, PKInstallPackageIdentifier=com.apple.pkg.iPhoneSDK5_0, NSUnderlyingError=0x7fdf882e8d40 "The file couldn’t be opened because it isn’t in the correct format."} {
I have no idea how to deal with this error or why it would be so.  Needless to say, it stops the entire install.  I downloaded the latest version of XCode just this morning.
I also thought of trying to install GCC by itself but the info on their site seems to be dated back to Darwin and not sure if the version they have there is applicable to Lion, plus I haven't done "MAKE" or any of the build type process since college.  Would like to avoid this approach if possible.
Can anyone offer any solutions.  I need to get going on Oracle review!
Regards,
Gerald

Answer 1

KT,
Should have said - 4.2.1 is the version.  I did another download while I was waiting for replies on this thread and am going to give it another shot.
Not running anti-virus yet - brand newmachine so haven't installed everything.  400gb free, hard drive passes any checks I've run on it.  I haven't looked outside to see the moon yet so not sure of that last one.
Why would I want to create a new user to run the freshly downloaded installer??
mallethead