I have created a series of fusion table layers and apply filtering to one of the layers in response to checkbox click events. The base layer of the map contains a gradient applied over county boundaries. When the base layer is unchecked, the filtered layer loses it's styling. I have added unique timestamps to all queries to avoid caching, however I get the feeling that these image tiles are still be cached for this situation. Is there any way to force the google fusion tables api to invalidate a cached image?

Test site here: http://map.inquestmarketing.com/new.html

Unchecking the Other -> Consumer Prospects checkbox reproduces the issue.

This is a pure client app, all of the source is in the single page.