I did create a bug report on this under the module that (I think) is the cause for this problem (FiveStar):
This is what I reported over there:
Unable to delete fields associated with module
1) Install Voting API/Fivestar
2) Add field to the content type in question where you wish the 5-Star rating to be enabled
3) Apply ratings to content
4) Attempt to disable the Fivestar module so it can be removed
5) Advised that fields associated with module must first be removed
6) Delete created fields found in content types 'manage fields' list
7) Still unable to disable 5-Star module as Drupal states fields associated with it are still 'pending' deletion
Manual Removal of Fields from Database
The problem lies with the fact that although the fields have been deleted from the manage fields list within the content type, they must still be present - somewhere - in the database. The only long-term solution that I can see in dealing with these 'ghost fields' as has been mentioned elsewhere on Drupal is to manually find them in the database and remove them from there.
While I do see similar reports made by others about 'ghost fields,' I do not think this is a Drupal core problem. If this were true I would think there would be far more reports being made. So, IMO the problem lies with the code associated with this module.
What I am looking for more immediate help with is how to find the 'ghost fields' in the database so they can be deleted, the module removed, etc. Short of completely re-building the entire site from scratch that is! Thanks for any advice.