I'm typing along and I want to create a preformat or numbered paragraph, so I open the drop-down menu and select "Preformat".  Then I want to start typing again but I can't do it: the drop-down menu widget is selected now, not my message.  Anything I type is lost.  So, I have to move my mouse back to wherever in the message I was last typing (which might well not be at the end, due to editing, signatures, etc.) and click there before I can start typing again.

This happens regardless of whether I am in text or html mode.

I understand that these items are "selectable" but I find this behavior extremely annoying; it really cuts down on my productivity.  As a couple of counterpoints, consider that selecting the bold, italic, or underline character styles doesn't de-select the text window; you just click them and keep typing.

Similarly, if I go to the Format -> Paragraph menu, then use the popup dialog to change the paragraph type, when I click OK my cursor goes right back to where I was typing, just as I'd expect.  Obviously this is all sorts of inconvenient in other ways.

Other information: