Ibatis Index Out of Range

Question

Im developing some sort of searcher using Ibatis.NET. So far, this is the sqlMap for the procedure:

 <statement id="statementId"  parameterClass="parameterObject" resultClass="resultClass">
  DECLARE @table1 Table1,
  @table2 Table2

  INSERT INTO @table1 (Value1, Value2)
  VALUES
  <iterate  property="valueList" open="(" close=")" conjunction="),(">
    #valueList[].Item1#,#valueList[].Item2#
  </iterate>
  INSERT INTO @table2 (Value1, Value2)
  VALUES
  <iterate  property="valueList2" open="(" close=")" conjunction="),(">
    #valueList2[].Item1#,#valueList2[].Item2#
  </iterate>


  EXEC [SP_StoredProcedure]
  @tvisible=@tvisible,
  @tparametro=@tparametro,
</statement>

StoredProcedure will return a set of columns that is determined by parameter table1. Problem comes when i make a call returning 4 values, and then make another call returning 3 values, i get an index out of range exception. I think that sqlDataReader tries to read the 4 columns that were returned before, but this time the set only consists of 3 columns.

Any suggestions to solve this will be appreciated.