Brian,
I am working in C3D2010 and having the same issue. I have a corridor modeled with multiple baselines, but sampled along the main road alignment (which is also the main base line in the corridor model.) I have base lines for other additional features in the same corridor model, such as ditches that do not run uniformly parallel to the main base line alignment. So the only way to get all of these features sampled and showing up in the section views is to create a surface from the corridor model, correct? (Which in that case you do not get to see the individual pavement layers- AC, base, etc., unless you create a surface-from-corridor for each.)
Brian is correct with versions up to 2011. 2012 can sample multiple baselines and show the sections as you want.
That is the advantages of subscription and implementing the new versions as they are released.
Miked,
Thanks for letting me know it has been addressed in C3D2012. My firm is in the process of upgrading to this version soon.