OK - I have managed to get the N900 to see the Global repository in addition to the UK one, and when I use:

'apt-get install mp-fremantle-generic-pr modest-providers-data'

in root it finds the package and unpacks it.

However, I now have the problem that I seem to have some corrupt dependencies in my distribution as the error message that now comes up is:

The following packages have unmet dependencies:
mp-fremantle-generic pr: Depends: libsdl-mixer1.2 (= 1:1.2.6-5+0m5)
E: Broken package

So, I'm guessting a previous attempt to use apt-get to update my distribution has broken something and is preventing the upgrade.

Is there a way to repair the above package, or am I looking at a reflash?

Disable the extras repository and run "apt-get install libsdl-mixer1.2=1:1.2.6-5+0m5"

Thanks - I had just worked it out. Had missed out the '1:' in the version number.

Now updating to pr1.3 fine!