Mahabharata: Rajasuya Yajna

                                                                  Q. Canto 1 Text 41 of chapter 9 purport: When the Rajasuya Yajna was performed by Maharaj Yudhisthira, Bhishmadev was present when first respect was offered to Lord Sri Krishna, and Sishupal was killed in that. But after the battle of Kurukshetra was over, Bhishmadev was lying on the bed of arrows. And in the purport Srila Prabhupada writes that Bhishmadev was present in the Rajasuya yajna performed after the battle of Kuruksetra was over. I am not able to understand this. If you so desire, kindly clarify the position.