Renaming packages on Mac OS X is sometimes a no-no - I found out the hard way when I renamed one of my InDesign CS2 Plug-Ins on Mac.

Packages on Mac OS X might look like files, but in reality they are folders, and in some cases there is a relation between the name of the package and its content - for example when the package contains an InDesign CS2 for Mac OS X Plug-In.

If you are developing your own plug-ins: if want to rename a plug-in the safest is to change the target name in your project, and re-generate the plug-in.