I've been trying to work out the themes and controlling idea for a longer story I'm starting on and when boiling down my ideas to that essence, I find that the problem between the characters is the same problem between them in almost every other story I've written about them. (I did think of one where it was different and, frankly, something always seemed off about the characterization in that story.)
Is this an issue for you when you write? Is it an issue? Do you have one version of the pairing or several? Does it seem to make a difference if the canon spans a longer length of time? If the scope of events is greater or lesser?
I've progressed from trying to analyse all the fanfic I've ever written to see if I do this will all my pairings to analysing my long-term relationship to look see if it fits the pattern, so I think I'll just stop for now and wait to see what you have to say instead. :)