scrbook and width of float

[Johannes Knaus]

Hello Lyx Users,

I have a problem regarding the width of floats.
I'm currently writing my thesis using scrbook (DIV=calc option).
When I create a float (happens with all types of floats) and write  
something into it which is wider than the textwidth, it is simply  
cropped at the page border.
How can I set up my floats to generally respect textwidth and if the  
content of the float is wider than textwidth it uses either a smaller  
fontsize or wrapping?

Thanks for your help.

Johannes