There was a problem installing “Mac OS X”. Try Reinstalling.

If you get this message after trying to clean install Lion from a USB drive (the install for me seemed to hang on my i7 MBP), you can try this as it worked for me:

1.  Power off the machine.

2.  Unplug the USB stick and power.

3.  Replace the USB stick, but in a different USB port.

4.  Hold down CMD-OPTION-P-R keys and turn the machine on (hold them until the machine reboots itself for a second BONG sound.)  This resets the PRAM, if you want to google it ;)

5.  Hold down Option and select your USB installer.

Should bring you to the familiar language selection screen.

Hope that helps.

PS-Hey Apple.  I applaud the diskless install, but why not let me choose clean install to begin with?  Restarting and “upgrading” just broke crap.  I broke more crap trying to get a fresh install.  Not easy.