I am generating a PDF document and displaying it in a Web browser (current version of IE is most important target). I want to suppress the floating toolbar (see below) that appears and disappears depending on mouse movement.
Is there a way to suppress this? I can control the PDF document (it’s built using itextpdf), as well as the Url.

What you’re looking for isn’t possible.
Read the answer by Leonard Rosenthol (Adobe’s PDF architect) on the iText mailing list: http://thread.gmane.org/gmane.comp.java.lib.itext.general/55112/focus=55120
Since version X of Adobe Reader, there is a new mode called “Read Mode”,
which is the default viewing mode when you open a PDF in a web browser.
In “Read Mode” you can find a semi-transparent floating toolbar containing
basic reading controls, such as page navigation, print and zoom.
Unchecking “Display in Read Mode by Default” can be done from Edit > Preferences > Internet
in Adobe Reader X but it there is no way to disable “read mode” programmatically.