Hi,
I've come across this error before but only if my original DW recordset has a parameter in it.
Sometimes when applying the Data Assist Search behaviour you lose the data type code of the end of the parameter (i.e "int" or "text") and so the page throws a wobbly.
Sometimes opening the recordset and closing it again fixes the problem, or you can just hand code the data type back into the recordset parameter.
Cheers
Ian