Freeverb doesn't work properly. Here's a description of the bug and a possible solution: http://music.columbia.edu/pipermail/linux-audio-user/2004-July/013489.html
could you please check if 1.16 resolves the problem ? I dont understand fully what's wrong, how to fix it, etc. but as this is an old bug I suppose the latest ladspa-cmt has fixed it.