these 2 icons (applications-internet.png, applications-other.png) are category icons so they should be installed into the categories folder instead of apps. http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html#guidelines
Created attachment 5817 kde with broken menus since app icons have a higher priority than category icons
Thanks for reporting this bug. This is resolved with this commit: http://git.xfce.org/xfce/exo/commit/?id=da5390d43977f9b80e4007360523be6fcb8a8574