Can someone please tell me why this formula will not allow a summary:

local NumberVar TotalPaid := 0;
local numbervar theAmount := 0;
local numbervar theRate := 0;

theAmount := {@CommissionableSalesPaid};
if {AR_Customer.UDF_INSIDE_REP}="DP" then theRate := .0085;

If {AR_Customer.UDF_INSIDE_REP}="KE" then
    TotalPaid := {@PaidFromKERate} + {#RTotal0};
If {AR_Customer.UDF_INSIDE_REP}="KE" and TotalPaid < 2000001 then
    theRate := .00125
Else if {AR_Customer.UDF_INSIDE_REP}="KE" and TotalPaid >= 2000001 and TotalPaid < 2300001 then
    theRate := .005
Else if {AR_Customer.UDF_INSIDE_REP}="KE" and TotalPaid >= 2300001 then
    theRate := .001;
theAmount * theRate

It does produce a numerical value for every line in the report.
{@PaidFromKERate} gets its value from a shared variable that is populated from a subreport in the report header of the main report, but even if I remove that, I still can't summarize on this field.

Thanks