Basemap slider issue with non-cached basemaps

Hi.  Playing around with the basemap slider, which is really cool.  I want to set up our aerial photo series as a slider.  We have bunch of map services, each one having a single year's photos.  1/2 of them are cached services, 1/2 are dynamic.

One issue seems to be that for the dynamic basemaps, in order for them to work correctly in the slider, they need to have default visibility turned on.  Obviously we don't want 18 layers turned on by default.  Has anyone else run into this?

Chris