Where do you get stuck?

I'm wondering what parts of a story/book are hardest for other writers to write.

I just pulled through a difficult chapter in my novel that took a really long time, and the problem (it seems to be the problem almost every time I get stuck) is that it was a transition.  Getting my characters to the next place I need them to be--quickly, logically, and without crossing the line between necessary exposition and info dump--is the part of writing that makes me struggle the most.  When trying to figure out such a transition I am most likely to stare at a blank screen, get distracted, and complain about just how difficult writing really is.  Give me an action scene any day--I can get it out much more quickly and easily.

My husband has the same issue, although he tends to outline his work first, so he goes through his struggles during the outline phase.  Once he's actually writing, he knows what's supposed to come next.  How do the rest of you weigh in on this?