This has been bugging me for some time. When I scan a paper form, I want to use the Typewriter feature to complete the form fields without going thru the trouble of building each field as a form field.
The Typewriter is enabled, but I cannot change the font size....or type. It appears to be inherited from an earlier usage of the typewriter settings. Same applies to a text box.
What characteristic or setting causes this issue or is it an Acrobat 9 bug ?
I'd have to say it is not an Acrobat 9 bug.
Working with scanned images:
With Acrobat Pro Extended (at 9.3.3) I can open the typewriter toolbar and, with the Typewriter selected, enter text.
While focus on the region used by the Typewriter, the toolbar provides the ability to make text smaller or larger, adjust line spacing, change text color, change font (as provided by fonts the OS is aware of) and change font size (fwiw, these last three configuration options are not present in Acrobat 8.2.3).
For any text box I place and for the text entered I can use the Properties Bar to configure the text box properties or the text's properties (as a function of where focus is) (same ability with Acrobat 8.2.3).
Perhaps a "Repair Acrobat Installation" or (if applicable) an update to 9.3.3 might resolve the problems you are experiencing (?).
Be well...
Be well...