TDS on Service Tax

DEAR FRIENDS, I AM HIGLY CONFUSED REGARDING TAX DEDUCTION AT SOURCE WHEN THERE IS A SERVICE TAX ELEMENT IN THE INVOICE. SOME SAY THAT RENT U/S 194 I  IS AN EXCEPTIONAL CASE I.E TAX SHOULD BE DEDUCTED ONLY ON THE RENT AMOUNT AND NOT ON THE AMOUNT INCLUDING  SERVICE TAX AND SOME SAY THAT ONLY IN THE CASE OF RENT IS TAX TO BE DEDUCTED ON THE SERVICE TAX COMPONENT AND IN ALL OTHER CASES TAX IS TO DEDUCTED ON THE AMOUNT EXCLUDING SERVICE TAX COMPONENT..CAN YOU RESPECTED MEMBERS,  PLEASE CLARIFY? IF POSSIBLE ASLO ATTACH THE RELEVANT CLARIFICATION FROM CBDT.. ILL BE HIGHLY GRATEFUL..