You can use this SQL QUERY to find all the forms for the entities in your CRM database. If you keep having duplicate Quick Create or Information forms come up, you can just look at this and see which forms have duplicate Type forms.

SQL Query:
USE YOURORGHERE_MSCRM
SELECT form.Type, form.ObjectTypeCode, e.Name, form.Name, IsDefault, form.IsCustomizable, form.PublishedOn, form.IntroducedVersion
FROM SystemForm as form
INNER JOIN Entity e ON form.ObjectTypeCode = e.ObjectTypeCode
WHERE FormPresentation = 1 AND FormActivationState = 1 AND Form.CanBeDeleted = 1 AND form.IsManaged = 0 -- just get unmanaged ones
ORDER BY form.ObjectTypeCode DESC