I am using a view which includes a field with multiple values. I do not want that, due to that field, some rows are shown more than once. There for I set "Multiple field settings" to "Display all values in the same row".
But Views Calc counts nevertheless the rows that have more than one value within that field as if it where not grouped:

| NR | field with single value    |   field with multiple value     |  field to calc  |
|----|----------------------------|------------------------------ --|-----------------|
|  1 | Some value                 | value1, value2, value3          |    1            |
|----|----------------------------|---------------------------------|-----------------|
|  2 | An other value             | value1                          |    5            |
|----|----------------------------|---------------------------------|-----------------|
|  3 | Something                  | value1, value2                  |    2            |
|----|----------------------------|---------------------------------|-----------------|
| Total SUM                                                              12           |
|-------------------------------------------------------------------------------------|
|-------------------------------------------------------------------------------------|

The example shows how the module calcs, but I would expect 8 as result.

Comments

I have encountered exactly the same thing. My example is a view of page view statistics of a content type (journal articles) where there are multiple authors per article. The authors are displayed in one row with a comma separator. The required SUM is the total number of page views of the content type. The actual SUM displayed is the SUM (number of authors x page reads).

If I remove the multiple author field from the view, the SUM returns to the correct value.