Hmmm.. here i would suggest something a bit "akward" but
interesting.... How about "Curve Flow" ?
Look what i did.... Created a simple curve and a nurbs circle.
Select first circle then shiftselect curve
Effects -> Curve Flow... ( no emmiter , just go with defaults for now)
Then i have several circles along my curve...
Now ... Select these circles and
Surfaces -> Revolve
Then from outliner quickly delete all unwanted stuff...
How about that... This must be the most Indirect way to
get some spheres along a curve
You know, there are at least two ways of getting things done... Your way and the right way...