[kronolith] error with sql

[Andre Grove]

I am running IMP with Horde and am wanting to use Kronolith as well.
I have set the driver as SQL in conf.php for kronolith and entered all 
the db connection info, but when I login on horde i get:

Fatal error: Call to undefined function: iswarning() in 
/var/www/html/horde/kronolith/lib/Driver/sql.php on line 64

The packages I am using are:

horde-2.2.3-1.noarch.rpm
imp-3.2.1-1.noarch.rpm
kronolith-1.0-2.noarch.rpm
php-4.2.2-0horde3.i386.rpm
php-imap-4.2.2-0horde3.i386.rpm
php-mysql-4.2.2-0horde3.i386.rpm
turba-1.2-1.noarch.rpm

Does anyone know what is causing this?

Thanks
Andre