Relief cal u/s 89(1)

Hi friends

I have a query regarding the Arrears of salary received i,e ( Pension ) one of my client  he had received the Revised pension from 01.01.2006 to 30.06.2010 for 4 yrs , He is a Senior Citizen above  65 yrs DOB is 15.03.1930 , I  had calculated the Relief u/s 89(1) and i am also attaching the excell sheet , because i am not geting the idea why it is showing tax liability in A.Y 10-11 as  28000 as his total income is below the Exemption limit of Rs 240000/- and also in A.Y 09-10 as tax liab 25000/- 

I have attached the Excell sheet to ........

plz give the idea where i am gone wrong or it is correct pls guide me .........

Thanks in Advance