My first thought as I read your OP was that the key isn't set correctly. If that's the case, your soloist is following lets say, the default scale of C major and the band is playing in B major.

You want to double check that to be sure the keys are properly set.

Having said that, I tend to work a lot in the country genre. Several of my songs actually modulate in the song..... moving up from one key to the next, and IIRC, some of that was IN a solo. This is one of them.... http://soundclick.com/share.cfm?id=13017714 fiddle is playing in the modulation and nails the change perfectly.

I also do not use BB and F5 to do this.... I move the tracks to Sonar as complete tracks and use envelopes to do the automation.

Instead of trying to set up the automation in BiaB with F5... try this. Write the song in BB and get the structure right....intro, verses, choruses, bridges, and outtros....save it and close it and close BB. Then open it in Real Band. It will generate all of the tracks into waves or the equivalent. Export those tracks one by one to your DAW. Finish your work in the DAW and automate in the DAW.

That's the way I do my work and everything works and sounds like it's supposed to sound.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.