Electrical systems dies - help!

[Namba]

I'm having a problem that I hope someone can help me with.

Sometimes when I turn the key to the start position and the lights come one, I press the electronic start button and the electrical system simply shuts off and dies. There is a "click" which immediately precedes the system dying.

In order to get the electrical system to work again, I have to disconnect the battery and then reattach it once again. Once I do this the electrical system works once again. When I turn the key to the start position I can usually start my bike normally.

What is causing the electrical system to simply shut down and why does it work again after the battery has been unattached and then reattached?