Late application u/s 154

Dear All,

We have come to know a demand of AY 2005-06, recently. We have filed the rectification application u/s 154. However the AO says the application is bad in law as it was not made within 4 years. We have checked our files, we have not received any communication u/s 143(1).

Does anyone know any case where a decision is made in favour of assessee.

Can anyone suggest what should be done.

Thanks