Perhaps it has something to do with the PDF you're viewing -- maybe the PDF is "protected."
Can you try making a "test" PDF by simply entering some text in TextEdit, then using the Print function to make a PDF, then try using those tools with that PDF?
Weird! It worked! Well, for that file at least...
But the strangest thing is that all my photos are like that now... and I'm pretty sure I could use the scroll tool on them before I upgraded to Tiger...