So, I've realized that one of CS4's undocumented features is resolution independent filters for MCs. Here's and example from the same file in CS3 and CS4 of the glow filter at a zoom of 400%.

My problem is this behavior seems to work in some instances and not others. almost randomly with different behaviors on different clips in the same movie. Is there something that needs to be done to the MC in order to get the filter to not cache the MC as a bitmap at a certain size?

This is a problem for me because I'm working on a file at a rez of 711x400 for to cut down on processor use, but am exporting video at 720p. When I do this filtered MCs stay at their original rastered DPI and look blocky. Any help is appreciated. I don't want to have to scale the whole movie in Flash to 1280x720. No computer could handle it.