In case the mistake I just made helps anyone else...
I wanted to display a file on a page with a default install of PW. So I added a field of type 'file' and rather unimaginatively called it "Files".
Via the admin I then edited a page and added a file and description to a page and added:
foreach($page->files as $file) {
echo "<p>Test output: {$file->description}</p>";
}
to the template.
The result was nothing new displayed :/ Confused I tried lots of things, then wondered if by using the name "Files" for my field I had stumbled on a reserved word that didn't work.
Of course everyone will have seen my error, the field I added was "Files" and the field I am querying is "files".
Lesson well and truly learned (I hope )