S100 movie mode

I must apologize in advance in that I have not read the manual but I am having a problem with my S100 in movie mode.

I set the top mode dial in the movie mode. Then in a dimly lit room at wide angle I activate the ev dial and crank it up to full brightness to get the brightest exposure that I can. When I activate the zoom to full telephoto it naturally darkens the scene; however, when I zoom back to wide angle it stays dark. Is this a bug or am I doing something wrong?