I can't help Tootler, except to say I've just had the same problem, so he won't feel so alone!

I've got a dual boot setup using Windows XP and Ubuntu 9.10. I have a FAT partition for data so that I can get to it from either OS. I'm using the default Firefox browser and Evince Document Viewer 2.28.1.

As Mr Codger said, the tax site handles all the data input through encrypted web pages, then when you've finished it offers you the opportunity to print or download a pdf version of the finished form.

It wouldn't let me save it to my FAT partition, but it did save to my home folder in Linux and will open there. When I manually copy it from Linux to the FAT partition, it refuses to open "Error opening file: Permission denied".

The permissions look OK and according to Evince there's no security on the pdf (I'm surprised at that, I'd have expected it to be protected from editing at least).

Very odd, and annoying.