Purchasing the Deed Subject to and the Due on Sale Clause

[Howard C]

I have come to an agreement with the seller who is looking to sell his deed to me, subject to the current mortgage he has with the lender. He is doing a quit-claim to me for a 25K fee. My concern has to with the "due on sale" clause that exists in his mortgage, and most, in general. Has anybody heard or actually experienced the lender calling the note due and actually exercising this clause. If so, how much time did the bank give you to pay the note off before commencing foreclosure?