Style Configuration Problems

[davidj]

I have my Preferences configured like the attached screen capture. All works well. I had, however, used these settings WITH THE EXCEPTION that for a while I had the "Compose Text as" box set to Enriched and for a while as HTML. For both Enriched and HTML I would be typing a message fine for a few lines and then without warning the cursor would jump to the top of the email message pane. Why? Can I configure things differently to use those settings and have the program work correctly? Is this a Bug in the program? My assumption is that my newness to the program has led me to incorrectly configure it. I look forward to your assistance.

[davidj]

Preferences Screen Capture