Migrating from G4 Powermac to G5 Xserve

Recently upgraded to a G5 Xserve to replace my old clunker Powermac G4. I've tried to image the drive from the G4 onto the G5 system and everything imaged successfully. For whatever reason, though, the XServer will boot up - find the OS partition - begin to load (white apple screen with spinning wheel) and then shut itself down.

The way I imaged it was 2 different ways: once with Disk Utility off of the Install DVD, and the other way was a restore from Time machine backup (in case the data was corrupt from the G4's drive).

I'm kind of at a loss for what to do here. I host several sites and have many user accounts in OD setup and going through and trying to migrate all that data by copying individual files seems a bit extreme.

 

I'm sorry, I should have specified that I'm running 10.5 server. There is no migration assistant. But I think this post pointed me in a good direction: http://forums.macrumors.com/showthread.php?t=781714

I'll try that tonight when I get home and see how it fares.