Load EQ, change UIs to the non-working one (with the bad target window in place) and when EQ reverts to the default UI, alt-tab or window-key out of EQ, and find the UIErrors.txt in your main EQ folder. Zip that up and attach it to this thread.
Or...
We could take this to emails and spare the community my bumbling.
I'm at
[email protected]
-Darl