Deposit held for a Periodic Tenancy which commenced in 2006

Tenancy Deposits

I have a Tenant who paid a deposit in May 2006 for a tenancy which commeced on 1st May 2006 and is still running. The Tenancy agreement contains the following clauses:-

1. The tenancy shall be for a fixed term of six months from 1st May 2006 until 31st October 2006 inclusive.

2. If, at the end of this fixed term you wish to continue the tenancy and you have not already received from us two months’ notice to end the tenancy, it will carry on from month to month as a monthly contractual tenancy. You must give one month’s notice to end it. We may terminate this agreement by giving you not less than two months notice. Notice must be given to expire on the last day of a monthly rent period.

The terms and conditions of the tenancy have not changed and the rent has not changed.

Questions:-
a) Do I have to protect the Deposit in these circumstances ?
b) Do I have to protect the deposit if the rent changes ?

Many thanks for your kind assistance.

Colin