Tried to use FilterList widget with a view menu or a normal header? this is a problem because they collided with the filter field once a letter is typed, because the filter field does not honor the height setting.
to over come it , add a class to your FilterListWidget and in the CSS do that: .[Filter List Class] .filter-field-container {
top: 0px;
left: 0px;
position: fixed;
...
