WordPress Widgets All got deleted

I was adding a text widget to my site, pressed save and when I refreshed my page, all the widgets I use on my site were gone.

I then went back to my widgets area in the backed and all my test widget areas were gone.

Why did this happen?

I am having my site restored, because I had alot of text widgets.

But I am afraid this problem might happen again, and I would like to lear what caused it, and what I can do to prevent it from happening again.

Thanks for your help in advance
Ryan