If you are playing on an Oceanic realm, you do not yet have the 3.3.5 patch on your realm and therefore should *not* have upgraded your copy of nUI yet... as the release notes for the update stated, it was for the 3.3.5 patch. It will not work if your realm has not yet been updated. You can fix this by going to the nUI download page at
http://files.nUIaddon.com and clicking on the "Archived" page... download the 5.06.20 release to roll back to the most recent pre-3.3.5 version of nUI. You can do the upgrade after Blizz patches your realm
If your realm has been updated to 3.3.5 and you have installed nUI 5.06.23 and you are still getting broken unit frames, I guarantee you it is another addon or nUI plugin that is causing the problem. To fix this, disable *ALL* of your addons except nUI itself -- this includes all nUI plugins. Log in to WoW and nUI should load correctly. Once you've gotten to that point, you can start enabling mods one at a time until you find the one that it breaking the load.
It is known the pre-3.3.5 versions of Prat, Chatter, WIM, HitsMode and Carbonite will cause the load to break along with the pre-3.3.5 versions of Xrystal's info panel chat plugins. I don't know what other mods may also have issues.