[turba] turba contact manager

[Ronald Cox]

While trying to add a contact into the address book
i recieve this error message while saving the entry..
Fatal error: Call to undefined function: is_a() in /var/www/html/horde/turba/lib/Source.php on line 287
if i go back to the address and view the book i can see the entry that i made.
can anyone help.
just want to get rid of this darn error message
thank you for your help
Ron  email: ron at reccommunications.com