It would be good to see your javascript that gets the query object and sets the param.x's.
If you know the query template works with the test param.x values, and you can confirm that the same exact query is referenced by the iCommand applet (assumed) then it might be in the script.
If the DB update is actually happening for the original param, then you're not producing a syntax error in the query, so the NetWeaver logs might not show you anything (but never hurts to check).