Just in case somebody else is getting this error I thought I'd leave this here.
I have a shopping cart that is stored in a session variable. When at item is
added or updated I do a sum of the quantity with a group by. I kept getting a
casting error on the quantity field even when I set the quantity=0 in the code.
I ended up having to do <cfset session.cart.quantity[row]=val(0)> instead of
<cfset session.cart.quantity[row]=0> I thought this was really weird,but hopes
this saves somebody else some trouble.