If a filter is applied on a group (including Inkscape Layers, which can be done by manually adding the style with XML Editor), editing the filter does not update the rendering of the group unless the filter is reapplied manually, or toggling the visibility of the layer (can be the layer itself which the filter is applied on).
Example steps to reproduce:
1. Draw two shapes.
2. Group the two shapes.
3. Create a filter in the "Filter Editor" and add a "Flood" effect. (The group should be filled with the flood colour but this doesn't happen immediately.)
4. Hide and unhide the current layer to see the filter effect applied.
5. Change the "Flood Color". (The rendered colour should change but doesn't.)
Also affects objects like 3dboxes (internally stored as group containing 6 paths) when merging multiple preset filter effects (see duplicate bug #1435078).
Affects versions: rev >= 12648 (inc. 0.91)
Regression introduced on: rev 12648 http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/12648
Reproduced on OS X 10.7.5 with 0.91 r13725 and 0.91+devel r13941;
tests with archived builds confirm that the regression seems to be a side-effect of r12648 (fix for bug #304407).