You're welcome... It's works for me and I just did two real simple examples, as follows:
First Example:
1. Created a new tune and entered chords for 12 bars and changed appropriate settings for bars/chorus star and end. Three choruses.
2. Selected style button next to the tune info window
3. Selected Samba (real style from Real Styles Classic)
4. Played the tune.
5. RC on bar 1, Bar Settings for Bar1
6. Selected chorus #2 in chorus pulldown
7. Clicked STY button under the chorus pulldown
8. Selected _JSWINGP
9. Played the tune.
First chorus played Samba
Second chorus played Swing
Third chorus played Samba
* You can see the style names change in the info box (if you don't have lyrics covering the info (another bug).
Worked fine.

Second Example
1. thru 4 as above
5. RC on bar 5, Bar Settings for Bar5
6. Selected All Choruses
7. Clicked STY button
8. Selected _JSWINGP
9. RC on bar 9, Bar Settings for Bar 9
10. Selected All Choruses
11. Clicked STY button
12. Selected Samba
13. Played the tune.
All chorues played Samba bars 1-4, Swing bars 5-8, Samba bars 9-12
All are real styles with their default real tracks.
If you want to change a particular real track instead of the default track of the style, then, it's the same as selecting a real track for soloing and you can put that realtrack on any of the tracks (as PG Music person said). I usually use Soloist, Strings, Guitar for these (I play guitar so I don't need the PG one's).

If you do change the default track, you'll need to mute the default track (eg, if you add a bass real track to Soloist track, then mute the Bass track).

Anyway, it works but, as I said (and I can't underscore it enough and hope the PG Music folk take heart), while this is a good feature, the lack of user friendliness will keep it from being a GREAT feature (and a program is only as good as it's user friendliness, despite the bells and whistles).