notice period after completion of probation but not confirme

dear friend,

Please guide me on the following :

I was on probation for a period of six months which expired on 31st July, 08. there is no clause of automatic renewal or mention that the probation is extended until confirmation letter issued.

But now i want to resign. However as per the clause during probation I was to give one month notice. Since they neither extended or confirmed my services do I need to give the notice period. I am willing to gorego my salary but the bad man insists that I serve the notice period. Please do advise. For your information I am reproducing below the clause :

with refere...... you are on probation for a period of six months in our Instite at Bangalore on a basic salary of....................... in the grade ................ You will be eligible for following allowances in addtion to basic salary.

In the event of your leaving the services of the Institute or the Institute intending to dispense with your services it will be requied to serve one month notice to each other or pay in lieu thereof.

Please help.

Regards
Padma