So far as I know, this is not possible - the component input always uses the scaler. The "Aspect Ratio" function depends upon the scaler to operate.
The implication is that there is always an A/D conversion followed by "Advanced Accublend" scaling which transforms the input signal to native 1024X768, followed by D/A conversion to drive the panel.
The only way I know of to avoid the internal scaler is to drive the projector with a proper 1024X768 signal via RGBHV after selecting "Native" in the projector menu. The "Aspect Ratio" function will be disabled.
The implication is that there will always be a significant improvement in the displayed signal if the source is a properly configured HTPC, versus any component video source such as a progressive scan DVD player or HDTV settop box.
Gary