Logic-Puzzles.org is a web-application, and as such it can perform quite differently on different computers, different browsers, international keyboards, etc. We're constantly working to improve the system and eradicate bugs as and when they appear. If you have experienced a problem or possible bug on Logic-Puzzles.org it would be an enormous help if you could report it using the following form. The more information you provide about the problem and the environment in which is occurred, the more likely we are to find and implement a speedy solution. Thanks for your help!