I just got an email from a reader (wow, nice to know SOMEONE is reading the book) about some confusion surrounding workflow forms.  I think I cover this somewhere in the book (it’s hard to remember everything in there when you’re old like me), and Microsoft covers it in a blog entry (http://blogs.msdn.com/sharepoint/archive/2006/11/26/developing-workflows-in-vs-part-4-design-and-bind-your-forms.aspx), but here it is again because I think it may be confusing to some people:

InfoPath document != workflow form.

From the SharePoint Team blog:

Pitfall: Confusing the IP document with an IP workflow form
A trap that people run into is thinking that a workflow IP form is the same as an IP document that is saved as an xml file (such as a forms library document).  If you are designing a workflow for a forms library, think of the library’s form template as an ordinary document, and the workflow forms as process UI.  Workflow forms are not files that are saved; they are merely UI to collect data, and the results are passed into the workflow, not a file.