Also, keep in mind you have to roll the entire withdrawal into a new IRA.
Sometimes, when they send you a check to close out a retirement account, they withhold some of the balance for taxes - so the balance of the old 401k could have been $111, but they only sent you $100, and withheld $11 for taxes.
You're responsible for re-depositing $111, not $100, within 60 days.