After installing UniDac 4.0.1 (full install), many existing Delphi 7 COM library projects would open with the warning "A unit named xxx has the same name as the type library's source unit. Unit will be closed", where xxx was the library's own auto-generated _TLB.pas file. Opening a project group containing 20+ libraries required closing every single dialog that popped up, every time the project or group was loaded.
Even a freshly made project would exhibit this behaviour. (File>New>Other>ActiveX>ActiveX library, then add an Automation Object to that project)
Reinstalling with a custom install using only the "UniDac files" (mandatory) and "UniDac providers" options removed the annoying warning popups, so I suspect one of the Delphi palette additions from UniDac causes this problem. Since at this time we only require the providers, this solved the problem for us, at least for the time being.