If I use this skin http://webix.com/skin-builder/768cc859 I get issues with the pivot configuration’s drag and drop. I’ll try to drop a column into any of the 4 boxes and it takes several tries to get it to stick. Its a very noticeable difference compared to just the samples.
Also it looks like the skin builder is using version 4.0 instead of the latest version - not sure if this has something to do with it either.