I have just bought a second-hand Status Vintage P bass in virtually mint condition. It's a lovely instrument - but there is one slight niggle I have with it: uneven string volume.

Basically the E and G strings are quite a bit quieter than than the A and D strings.

String height relative to the pickup is all okay in relation to the relief of the neck, so the only thing I could think of was maybe raising the pickups pole pieces. Would this be effective or not?

Looking at the picture of the pickup, you can see that each pole piece has a screwhead style top to it - so they should be adjustable, right?

Here's the pickup in question

dammit - technical difficulties attaching the image...:@

To quote Rob Green (see FAQ at the Status Graphite Website):
The closer the pickup is to the string the greater the output but this goes up exponentially
so if you make the gap half as much the output can be up to ten times not just twice.
If you are unsure what to do or have any problems please leave any adjustment to a professional guitar technician.

I hope that helps to set up your pickup. :)