Title Issue selling even with Title Insurance

[Kevin Polite]

We purchased a home before it went into foreclosure directly from an individual. We used an attorney and got title insurance. We remodeled and have a solid contract. The attorney for the buyer is the father of the couple.
He keeps trying to complete the title back 20 years even though we have a title insurance. Our P&A states they only need to be able to get title insurance. The seller to us had no liens, but there 2 other people with similiar names, but different addresses and he wants a "No Me" Affidivat.

Am I missing something here? Is he being overzealous? we gave them 45 days to close, their loan is fine, their due dilligence is completed, if they don't close on scheduled date should we refuse unless they lower the closing cost we offered? I'm sick of their agent and they backed out once before. We had 3 offers on 3 consecutive days AFTER we signed the deal with them so I'm confident we can sale, but we're getting close to the holidays.
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