no problem for been "late", most people here disappear in eternal silence it seems :-)
Well, I threw the WOW-slider away, but what happened was that a (dotted) right-border I put was been segmented and the segments were added to the left side of that border, only next to the slider. The rest of the column was OK.
There was as expected a normal border, covering the whole side. The 2 or 3 new segments started at the column-top, parallel to the normal border, getting progressively shorter.
It seems like the plugin calculated additional hight for the border when the slider was there and tried to fit it in the existing hight.
Also another strange behavior was when the slider was above the (3) columns, (itself not in a column like above). Their tops started higher than the text. Normally they start ± at the same hight. I solved this by adding top-margin in the element's css.