[giapeto] Options error

[horde@ovsc.it]

Hello All:
Could somebody please help me with a problem I am having?
I installed and configured 'giapeto' and everything work all right.
I can even make pages!
But I cannot enter the 'options' page: I get that error:

"Fatal error: Call to a member function getThisPageId() on a non-object in
/my-path-to/horde/giapeto/lib/Giapeto.php on line 922"

Any idea?

Thanks a lot

Giuliano