pdf with non-vector fonts

Hey all,
I'm generating pdf files using QwtPlotRenderer like in the bode example. My problem can also be duplicated with the bode example. I'm seeing the problem both on Mac's and PC's using qt 4.7 and qwt 6.0.0-rc5.

When exporting to a pdf file, all graphics generated are vectors. Is there any way to make the fonts not be vectors and leave everything else as vectors? The users of my product may want to import the pdf file into another package to modify it for publication. They'd like to be able to modify the text in the title, axis, legends etc. Modifying fonts that have been converted into vectors is a lot more work. Can anyone think of a way I can set up things differently so the fonts are exported as non-vector fonts?

Thanks in advance for any help,