JFTR - same behavior with Inkscape 0.47, 0.48.5, 0.91, 0.92.0 and 0.92.x r15313 (on OS X 10.7.5).
What always worked and still works (as with other path effects): group the path with the path effect applied and scale the group instead, if the exact output at the current scale is to be preserved.
JFTR - same behavior with Inkscape 0.47, 0.48.5, 0.91, 0.92.0 and 0.92.x r15313 (on OS X 10.7.5).
What always worked and still works (as with other path effects): group the path with the path effect applied and scale the group instead, if the exact output at the current scale is to be preserved.