nah, VGA can output a 16:9 ratio resolution. More likely it is a limitation of your graphics hardware and it not supporting any 16:9 resolutions....
Although the VGA input of your HDTV might limit the resolution....check your HDTV manual to check what resolution(s) are supported via the VGA input.
You need to A. determine what input resolutions are supported by the HDTV and via what ports (VGA/DVI/HDMI)
And B. What output resolutions are supported by your laptop and via what ports.
As an example, the Macbook, in general, supports external displays up to 1900 x 1200 on Apple DVI displays but only 1600 x 1200 via VGA so if you are using the VGA output on a Macbook, it might be part of the problem.