WordPerfect 10 Questions

I'm starting a new position soon, and I have two questions.

1. Do WP 11 and WP 10 save to WP 5.1 the same way, i.e., will my line counts be same saving to WP 5.1. from either 11 or 10?

2. I updated my WP 10 to Service Pack 3, and I no longer have the option to Save As WP 5.1 format. Any ideas?

Thanks!
Deb