According to Friday's Tuttosport ( yes, i know
) Milan offered 40 M Eur to Juve for Buffon ( the same ammount Juve payed to Parma) and Juve rejected the offer.
Few hours after Tuttosport wrote this Dida signed his new contract with Milan.
As much as Tuttosport is unreliable and as much as 40 M Eur seem unbelievable, i won't be suprised if Milan did make the final attempt on Buffon and when Juve rejected the offer you decided to keep Dida !