Thanks for the prompt response Pete,
I have no idea either why that happens...
I tried to introduce some spelling errors in the word "Wirral" and then everything works fine.. It also works fine if the location only contains the word Wirral (i.e. "Wirral%2C+North+West.+UK", "Wirral%2C+England", etc..). Not sure if that helps the troubleshooting.. :-/
My first thought would be that maybe there is a variable called "wirral" and that might screw up the process.. But that's hard to say without looking at the code.. and I'm not a programmer either so I might be talking rubbish :D