Are you saying they do not offer PHP 5.2, as in they only have 5.1.x? Or are they only offering 5.2.9 which none of our versions works on because of array_unique bug?
Cause all our versions should work fine with any 5.2 version other then 5.2.9.
Dowgrading should be simple, the table changes involved should be fine on 4.2 as well, so it should be enough to overwrite the files and update version in db with:
UPDATE ezsite_data SET value='4.2.0' WHERE name='ezpublish-version';
