DATEADD not calculating correct totals

[Roseventura]

I've seen this work in other people's examples, but I can never get it to work in mine.

My DATEADD() measure is not calculating the correct totals for the previous month or previous quarter.  Here are my measures:

     Sales LM = calculate ( [Total Sales] , dateadd( PBI_FSCAPF[PADDATE], -1, MONTH ))

          and

     Sales LQ = calculate ( [Total Sales] , dateadd( PBI_FSCAPF[PADDATE], -1, QUARTER ))

PBI_FSCAPF is my date table and PADDATE is my date field formatted as mm/dd/yyyy.  YEAR-MO and YEAR-QTR are also in the date table.

Has anyone ever seen this before?

Thanks,

Rose