Is UK postcode proximity searching actually possible in 5.x?

Hi

OK, I have been tearing my hair out trying to get a proximity search view working using either the Proximity:postcode or Proximity: map method.

In 5.x-3.0-rc2 there seems to be no zipcodes.mysql as there was in previous versions (eg 5.x-2.7) to be imported into the database to create the correct 'zipcodes' table, into which the supplied 'zipcodes.uk.mysql' can be imported. Using the 'zipcodes.mysql' from the earlier release, I managed to create the table and import the UK postcode data (I think - browsing the table in phpmyadmin seemed to show all was present and correct, but I am not very familiar with SQL or doing much of anything in phpmyadmin other than creating a db)

I can expose the filters fine, but even when I have nodes with postcodes defined using the Location CCK, I submit a search for those postcodes and nothing is returned. The nodes seem to be geocoded ok as the markers appear on the Gmap in the Location block for each node. But they are not 'findable' in my Views query.

I'm sure this is possible in 5.x and just difficult for a relative noob, but if I am trying to do something not yet supported it would be good to know. It seems the Location Views options are all there, just... nothing happens.

My site will be so much better with this enabled, I really appreciate any advice at all on how to proceed with this.

Thanks.