Crystal Reports Sum Formula in Group

Message

   I have a formula that is inserting a "1" into the report if a job is a "warranty" job.  This formula is working.  Now, I want the "sum" of those items on the report.  Crystal 2008 is not letting me do it. 

The name of this formula is "Warranty"  It is working.
if GroupName ({WORK_ORDER.LOT_ID}) = "W" then 1

I created a second formula called "Warranty Count."  The formula that I attempted to use to "sum" the "1" totals is 

if {@Warranty} = 1 then Sum ({@Warranty})

Crystal 2008 is giving me an error, "This field cannot be summarized."  I also tried

if {@Warranty} = 1 then Count ({@Warranty})

Also tried 

Sum ( {@Warranty})

Same error, "This field cannot be summarized."  

Also, I cannot right click and "INSERT SUMMARY" into the report.  Crystal 2008 is not allowing it for this particular scenarios.  

 Any help is appreciated!

Edited by joshdooley - 27 Mar 2009 at 12:51pm