@VTWin: When you expand the project's search path with the path to package sources you are calling for trouble with the "duplicate units" error. I know delphi does this, but Lazarus uses packages - just add the package to the requirements of a project in order to be able to use its units. No fiddling around with the unit path!
@pk2: Did you recompile the package TAChart? But probably this will not work anyway. "typ.pas" is the central declaration unit numlib used by all other numlib files. So, when you recompile the TAChart package you will also recompile typ.pas, and the compiler will find the other comipiled numlib units to be outdated and will try to compile them as well. But their sources will not be found. It should work when you copy the other numlib files to TAChart as well. But you should be aware: Any change that you make to sources coming with Lazarus will be gone when you update to a new version!
Why do you want to copy typ.pas into the TAChart package?