"Last Saturday, missing chances knocked us out of the cup, and against Derby we made it hard for ourselves because we missed so many again," said Ferguson on MUTV.
"We were really charitable - it was a lot of chances. Maybe it's a little sticky spell, but we want to get over it.
"We've big, important games coming up, Bolton at home on Wednesday and then Liverpool on Sunday, and we want to start taking chances.
"We are making them, and I suppose that's the biggest bonus of all.
"If we keep making them, you know at some point someone's going to suffer. We just have to keep going with that."