I don't think so. When the drives were first presented in the Samsung HDD catalog (here's
a link to a
version of it), a 120 GB one platter model was also present. So far, there is nothing on Samsung's site about this model. It has been removed from this version of the .pdf, but not entirely: the model SP1212N is still present in the list in page two.
I can only imagine how hard it is to manufacture 125 GB platters at the moment; thus there's no point in "wasting" the platters in 120 GB drives, when they are needed in the 250 GB models, and 120 GB can be reached with 80 GB platters.
Also, the platters in the 200 GB model are only 100 GB, AFAIK.