Attaching reduced test case: possible trigger seems to be a disagreement about the clip-path itself (a group of 4 paths).
Reproduced with Firefox 12.0 Safari 5.1.4, Opera 12 and Chromium 22.0.1189.0 on OS X 10.7.4
Only Squiggle (Batik 1.7) agrees with Inkscape (0.48.x, current trunk).
Attaching reduced test case: possible trigger seems to be a disagreement about the clip-path itself (a group of 4 paths).
Reproduced with Firefox 12.0 Safari 5.1.4, Opera 12 and Chromium 22.0.1189.0 on OS X 10.7.4
Only Squiggle (Batik 1.7) agrees with Inkscape (0.48.x, current trunk).