Letter automatically "jumps" back - Where is the setting?

[Christian Morten Borge]

When I type in text Illustrator and push the long space button to make a space after a word and then start typing a new word the new new letter autmoatically "jumps" back and removes the space between the last typed word and the new letter/word typed. Where do I make a change to fix this problem?

[Monika Gause]

And this happens with Arial?

Which language is set up for the system, the keyboard and Illustrator?

Did you already try the obvious? A system reboot? Resetting the Illustrator preferences (which will erase all your settings)?