The highest resolution supported by the Acer X133 is 1920 x 1200 (WUXGA). That's over seven times the resolution of a 640 x 480 (VGA) projector, which is the most frequently found resolution supported by 13000:1 contrast ratio multimedia projectors that were released more than a year ago.
This multimedia projector's resolution (1920 x 1200 (WUXGA)) is actually the best supported resolution across all similar spec multimedia projectors that have been around for around the same time as the X133.
A 640 x 480 (VGA) graphics resolution is the worst supported resolution amongst comparable types of multimedia projector.
Projectors with a higher resolution that might also be worth considering include the Benq MS524 (£359.39) (1600 x 1200 (UXGA and cheaper)|640 x 480 (VGA and cheaper) and cheaper).