how do I set max_sleepPL to call the idle hook more frequently?

writing a plugin that allows blender to fetch precomp bitmaps from AE quickly via shared memory and am trying to make the idle hook get called enough times to support its target of playing back 30fps precomps. when I try to set *max_sleepPL in any of the stock plugins that use idle hooks though (grabba, mangler), it has no effect and max_sleep always gets reset back to its default value in the next idle hook call (1800 in grabba and 1000 in mangler). is there another step I'm forgetting to do to allow setting of the value?