In latest version downloaded yesterday to replace previous one, I also downloaded the postcodes zip file, extracting it to the same folder as the sky demon program files.

CWJ - I've just checked the search function using 'find' in SD plan and also on my 5 inch GPS unit and both work.

I've got the latest version so I think it must just be a minor glitch and not a bug in SD

I checked the location of the unzipped postcode file on my laptop and it's located in Documents > Skydemon, good luck with it.