Hey all,
I've been trying various styles; I really just want an uptempo swing with the bass walking at 4 straight notes per bar, but almost everything I've tried defaults to two notes per bar with the occasional pickup note. I'm interested in midi tracks at this time, not the real tracks.

I should specify, either 4 notes per bar at 260bpm or 8 notes per bar at 130. I've tried it both ways adjusting the chords per bar to compensate, but it doesn't seem to make a difference.

Which package (Pro, Mega, Ultra or Audiophile) do you have? The package determines how many styles you have available.

Is there a song that has a bass like you want? If so try a style search on the song name.

You can program the notes yourself. If you do this then move what you've programmed to the Melody or Soloist track so your programming isn't lost when you hit the regenerate button.

Thanks for the helpful hints!
After a little more fiddling about with various jazz styles, I realized many of them default to 2 notes per measure in the A section, and a few switch to 4 beats in the B section (the ones that do this are typically labeled as such in the style description), so I was able to get the proper feel by adjusting how I labeled the phrases.

Glad you got it worked out.

There are also several rockabilly bass RTs that walk. They tend toward more simple patterns than the jazz 4’s and have a more round sound as they stay on lower pitched notes.

If you're doing midi...write the extra notes in.

There are all great suggestions here, and it's great that you found that the B section works for you!

Another thing to test it to turn on simple arrangement for the track and re-generate, then see if that gives your desired effect. Click the track in the mixer and go to Track Settings | force track to simple arrangement. Also, adding a slash after the chord name, then enter a note name will put that note in the root position of the chord. For example C/E will put the E in root position of the C Major chord.