Access Calculation Error on Access 03 Report

[kerch17]

I am receiving an error when trying to do a summation for a field on an access report. The error is: "This expression is typed incorrectly, or it is to complex to be evaluated. For example, a numeric expression may contain too many complicated elements. Try simplifying the expression by assigning parts of the expression to variables."

The calculation that I am doing on the report is:
=(Int(Sum([drv_time_elapsed1])/60)) & ":" & Format(((Sum([drv_time_elapsed1])/60)-Int(Sum([drv_time_elapsed1])/60))*60,"00")

The field drv_time_elapsed1 is being created in a query:
drv_time_elapsed1: CInt(IIf(([drv_time_elapsed]=" "),0,([drv_time_elapsed])))

The query itself runs successfully, but when I try to sum the field on the report I get the error. I have even tried to simplify the sum, by just doing a basic sum: =Sum([drv_time_elapsed1]), and that doesn't work either.

Please help, I am ready to scream!!
Thanks
Laura

 

[pbsjr]

Your problem may be in handling NULL values. Access will not process an function containing a NULL without catching it with NZ funtion:

CInt(IIf((nz([drv_time_elapsed])=" "),0,(nz([drv_time_elapsed]))))