Apple Safari displaying http headers on the rendered page

Hello,

we have just installed and configured mod_layout with Apache 1.3.3 on  
Mac OS X (Darwin). With this module enabled, everything works  
correctly except for the fact that Apple Safari suddenly starts  
displaying the http headers on top of the rendered web page.

If mod_layout is disabled, everything is back to normal. Safari is  
the only browser that exhibits this behavior. Has anybody ever seen  
this or remedied such a situation.

Thanks for any hints.

Ralph Scheuer