We encountered an issue with horizontal repeating controls not wrapping in a particular case.
If you send the form in email and include a static copy of the form (rather than dynamic) the generated screen shot doesn't wrap the horizontal control, but rather stretches it out to infinity on the right.
The form renders fine interactively inside a table of specified width. It's only when emailing a static copy of the form that we've encountered the problem.
InfoPath 2007 BTR2
To HazenHills: thank you for reporting the issue. We are aware of this limitation; unfortunately, there is no good way to preserve the layout of this kind of form in the Outlook preview pane. One workaround would be to place the horizontal repeating section into a scrolling region: this will cut off everything outside of the borders of the scrolling region. Alternatively, you can attach the form XML with the email message, and the user will be able to see the correct layout by double-clicking on the email message.