I believe the "Chorus" plug-in is a "DMO Audio Effects" filter, probably provided by Microsoft.
If you uninstalled it from Plug-in manager, it should not be playing a role. To be sure, you can bring out DSP Studio while the audio is playing, and check to see which plug-in is being used (which one has the checkbox checked). All installed plug-ins show up in the DSP Studio, but only the ones with a check mark are being used.