How to handle width in filter pane

Hi All

I use a filter pane for my reporting with the BEx Application Designer. (BI AddOn 7.X – based on 7.3). When I change to the Web View and navigate with the filter everything works. Only the width of the filter pane varies depending on how many characters the text has.

I have tried to define the maximum number of characters in the Web Item Parameter but it doesn`t help. If the text is shorter than the maximum number of characters the width of filter pane mask in the web view gets smaller.

Is there anybody who knows how I can fix the width of the filter pane?

Thanks and Regards

Janine