Gamma problems

Well, im adjusting my gamma on my movieconfig, then cl_avidemo, then vdub. But I recently discovered that low gamma and high gamma gives the same gamma amount in virtualdub, also affecting vegas and movie programs. The worst of all: its dark. Do anyone know how I can turn this thingy off? Its kinda like when you perform a screenshot in ET, where the screenshot will be a lot darker than your normal gamma.