[SOLVED] Widget in Header are adds unexplainable height

Hi,
I just added a custom widget area to one of my blogs. But as soon as I put a widget in there, the widget area adds an additional 40-50px to the bottom of the widget area. It's white (or transparent) and I can't seem to get it away. I've double-checked all places I remember to use paddings, margins etc - nothing. I also remember that I encountered this before and even fixed it. I do not remember how, though.
Reproduce:
1. Add widget area re to header area (<?php bfa_widget_area('name=headerWidgets&cells=2&align_ 1=7&align_2=7&width_1=800'); ?>)
2. Check page: Nothing happened (correct)
3. Add widget to "headerWidget" area (e.g. an image with height 20)
4. Check page: Image is added as well as 40-50 px of space below it

Can you help me with this one? I'm using Atahualpa 3.4.4