sure seems like it... used to be (and i tested this on SW2009 I still have on my laptop) that entering a sketch on the surface of an imported STEP would allow snapping and autorelations. The sketch element would fully constrain...
On 2009 works like it has for the past 15 years
On 2010, with the same sys and doc snap settings and sketch settings, it doesn't
Try it - do a simple rectanglular base, add a few cylinders to a surface, make sure you draft them 1d inward
export to 214 STEP
Bring it into 2009 make sure snapping is enabled, ... do the diag, then add a sketch to the flat where the cylinders are. Grab the const line tool and add a segment.
Note the quad and center snap points appear
place it in the center of the cylinder at the snap point. Note the cursor turns to the snap symbol in a yellow box - complet the placement.
Note the line is fully contrained (black)
Now do the same in 2010. you get the quad and center snaps as you cros the cylinder, but when you go to the center to snap, the cursor snap symbol doesn't have the yellow background; the resulting sketch element is blue and can be moved.
What's really weird is if you export with a non-drafted cylinder, it works as expected....