[sork] warning message vacation

[li at elaboratio.com]

I'm using vacation HEAD version with Horde 3. It works fine but there is a
warning message.



Warning: Cannot modify header information - headers already sent by (output
started at /usr/local/www/horde/vacation/lib/Driver.php:2) in
/usr/local/www/horde/vacation/templates/common-header.inc on line 4

Warning: Cannot modify header information - headers already sent by (output
started at /usr/local/www/horde/vacation/lib/Driver.php:2) in
/usr/local/www/horde/vacation/templates/common-header.inc on line 5

Can somebody explain me why I get this warnings and how to fix it?
Thank You.