Milan thumped Shakhtar 4-1 to go top of their group and Ancelotti said: "Everything has not been resolved and we will probably run into certain problems again in the future.
"We have difficulties in certain games. In Europe there are more open teams and we can make the most of the characteristics of our players."
"Kaka did everything and more. He made a lot of mistakes in front of goal, but he was devastating when going forward at pace.
"Everything is so much easier with Kaka. The Ballon d'Or? He certainly did not need confirmation tonight for that award, he has already done more than enough to deserve it and will continue to impress."
Alberto Gilardino was the surprise pick upfront instead of Champions League specialist Filippo Inzaghi, but rewarded Ancelotti with an early brace of headers.
"Today Kaka had great help upfront, as Gilardino aided him in holding up the ball and scored two goals."
Only this week General Manager Adriano Galliani had complained that Milan did not have any strikers who were good in the air, but Gilardino netted two headers this evening.
"That's the great thing about football - you are immediately proved wrong at every turn!" grinned Ancelotti.