date parameter problems

Hello Im having a date problem

I have a parameter called @.Param_Daterange with the following values

Last 30 days =Today.AddDays(-30)

Last 60 days =Today.AddDays(-60)

My SQL has a chart which uses the following SQL

SELECT Sum(dbo.tbl_OMDQ_Aggregates.Value) AS SumOfValue, dbo.tbl_OMDQ_Aggregates.status_desc, dbo.tbl_OMDQ_Aggregates.DateRun
FROM dbo.tbl_OMDQ_Aggregates
WHERE (((dbo.tbl_OMDQ_Aggregates.SaleMonth) IN (@.Param_SaleMonth))and (status_desc IN (@.Param_ChurnType))) and dbo.tbl_OMDQ_Aggregates.DateRun > @.Param_DateRange
GROUP BY dbo.tbl_OMDQ_Aggregates.status_desc, dbo.tbl_OMDQ_Aggregates.DateRun;

In visual studio the chart is working fine, however in IE the data getting returned is only a small subset off the entire data, ...my IE language setting is at English Aus, I also created a textbox so i can see what value the daterange parameter is passing and it seems to be in the correct format...the graph is also in the right day/time format of dd/MM/yyyy. However i have no idea which date is getting passed incorrectly, somewhere the date is getting switched to American format however what is outputting on the screen is in the right format...just not the correct records are returning

can anyone please help

Fixed it !!! it wasnt the notorious Amercian format problem after all but rather the daterange parameter had turned into a string datatype for some reason..changed it back and all is well !!!