I have "possibly" got a fix:

http://########################.co.uk/versions/ukzr.txt

if you put this in includes/modules/shipping/ukzr.php overwriting your current file, it might work for you. (it's a text file on my server to stop it just splurging php). The current version of ukzr is bug-ridden, it will take a long time to sort out, it didn't take conversion to a new format that I am working on (to make moudle generation simpler) so this is a reversion to an older one that appears to work on my system although it does display an un-necessary parlforce loge, that I'm sure you can remove. Just put the file in place, do not remove and install as you may loose you work so far.

Thanks
Philip.