Filter rendering on canvas is not always working with 0.47pre0.1

[Yann Papouin]

As a 0.47pre0.1 user, I tried some filters.
Some are not rendered when object is small or when zoom view is reduced.

In prefs, filter quality is set to high.

Check attached svg, the rectangle shape is not visible with default settings.
Try to zoom in or change its size to show it with the filter applied.

[su_v (suv-lp)]

reproduced with Inkscape 0.47pre1 r21720 on OS X 10.5.7

[jazzynico (jazzynico)]

Confirmed on Ubuntu 9.04, Inkscape rev. 22023.
With filter quality set to Average, the objects is not rendered at all, whatever the zoom level is.

[jazzynico (jazzynico)]

Reproduced on Ubuntu 10.10, Inkscape 0.48.0-1ubuntu1.2.
Not reproduced with trunk revision 10444 (new Cairo renderer).