There was something about PDF & Smath. So, as long as Smath is "open"
1. Print[Smath]
2. Print to File at the print promp.
3. I selected "ScanSoft" [Nuance ~ $45 for life and from years old]
4. Give a name [typical C:\PDF Test]
5. Open back Adobe Reader XI [Freeware]

Nothing else is needed from Smath.

... the first image is from Adobe Reader nothing to do except zoom.
This image below is open with "Nuance" ... all imaginable functionalities.

What else do I need from Smath ? Answer: Nothing, perfect as is.
Smath is not a "PDF Creator". Get freeware and suffer or purchase
and be "Pro" at least at the Smath image.