Sidebar Text Widgets Disappeared !!!

Yesterday when I entered my website, I realized that sidebar text widgets have disappeared! I didn’t change anything, just entered my website and saw this issue, so I don’t know what’s happening, is it a WordPress issue or I have to write text widgets again?
I have WordPress 2.3.2 and I’m using Black-Letterhead Theme. Everything was working great and suddenly this happened. Thanks very much in advance for your help!

Greets,

Jorge.