RowFilter Compound Expression Problem

if you run the compound expressions separately then each does it's specific task nicely and does return the correct selection of rows - I have checked this. If you combine the LIKE expressions with the IN() expressions using OR, then none of the filtering works, instead you get all rows returned. no error messages and it runs. I spoke to severl other programmers about this and came to the conclusion that compound expressions must have limitations and may be some compound expressions do not work well with others. so I got impatient and programmed my way round the problem by selecting a row[] with the rows that meet the LIKE criteria, copying the ID's to a string and then combining that string with the string that previously went in the the IN() expression. so no compoind expressions, big use of the IN expression and doing long hand programming to get the correct selection string to go in to the IN() expression. this worked fine here is the code if your interested, though I haven't tidied it up yet (next job); public void FilterdataViews() { string[] ErrorArrayString = new string[System.Convert.ToInt32(dataViewFanucLog.Count)]; string[] KeywordArrayString = new string[System.Convert.ToInt32(dataViewFanucErrors.Count)]; string[] FanucArrayString = new string[System.Convert.ToInt32(dataViewFanucErrors.Count)]; string ErrorString = ""; string KeywordString = ""; string FanucString = ""; string FilterString = ""; int ErrorCounter = 0; int KeywordCounter = 0; int FanucCounter = 0; int i = 0; int j = 0; KeywordFilter2 = tboFanucErrorFiltered.Text; //this is where the keyword string comes from... string KeywordFilter = "Fanuc_Error_Code LIKE '%" + KeywordFilter2 + "%' or " + "Fanuc_Error_Message LIKE '%" + KeywordFilter2 + "%' or " + "Fanuc_Error_Description LIKE '%" + KeywordFilter2 + "%'"; //this is the LIKE search text // get a array of rows which match the LIKE criteria DataRow[] KeywordRows = ds1.Fanuc_Errors.Select(KeywordFilter,"Fanuc_ErrorID DESC"); //get the ID's of the rows returned foreach (DataRow R in KeywordRows) { KeywordArrayString[i] = R["Fanuc_ErrorID"].ToString(); KeywordString1 = KeywordString1 + KeywordArrayString[i] + ","; KeywordCounter++; i++; } i = 0; // get the row ID's of the rows that you want to do the IN() filter on... foreach (DataRowView V in dataViewFanucLog) { ErrorArrayString[i] = V["Fanuc_ErrorID"].ToString(); ErrorString = ErrorString + ErrorArrayString[i] + ","; ErrorCounter++; i++; } i=0; foreach (DataRowView V in dataViewFanucErrors) { FanucArrayString[i] = V["Fanuc_ErrorID"].ToString(); FanucCounter++; i++; } i = 0; //mess about with the array to exclude ID's you don't want...... for (i=0;i