Problem number one of the day - why does my keyboard insist on printing @ instead of " and vise versa?

Ah - that would be because I haven't set up my keyboard preferences. The problem is that US and UK keyboards send different signals for the same key sets.

In the menu click on System -> Preferences -> Keyboard and then click on the Layouts tab to bring up this:

As you can see the default is set as USA. If you are lucky your keyboard type will be in the drop down list under "Keyboard model."

To change the layout click on Add to bring up this:

You will see when you select the different layouts the different keysets appear. You could really confuse people by changing this! You can also alter the type of keyboard (querty, dvorak, mackintosh) by changing the variants tab.

Top tip: This will not change the keyboard layout for applications that are already running but next time you open them all your keyboard gremlins will be gone.