If you have a grouped query which includes a criteria based on a collection attribute and add this query to a dashboard as either a pie or bar chart you may see an incorrect count returned
For example if you have a query based on the incident object and a criteria of "Notes.Created By is Equal To ( SA )" so that only incidents with notes created by SA are listed on your query. In our example, if you had only 1 incident but with 3 notes created by SA, the dashboard will show a count of 3 incidents in the pie chart instead of the correct value of 1.
If you need to have the collection criteria on your query, using a count panel on the dashboard instead of the pie chart or a bar chart will return the correct count value. In our example, using a count panel would return a correct count of 1.
This issue has been raised as problem 3933 to be addressed in a future release.