Ahha! Looks like I stumbled across a fix by accident (and slightly frustrated).
There's a forum post (viewtopic.php?f=1&t=9198) that shows a consolidated list of problems in LUI 3.7, one of them was the Player and Target UnitFrames.
The fix in that forum link did the trick for me, all is good now:
Chaoslux wrote: Try this: Quote: Open LUI.lua in your LUI folder (NOT WTF folder !) and then goto Line 1273 and 1274 and change the disabled value to enabled, save it and then start the launcher and login. Then create some new profiles.
Hopefully it also fixes the same issue for anyone else having the problem!
PS. If anyone is wanting to know how to modify a .lua file, use Notepad++. It's freeware and worked beautifully for me.