[horde] Upgrading from 3 to 4

[Chris]

Hello.

I'm trying to upgrade from horde 3.3.8 to the recent version of 4.  I  
have a freshly updated OS of Debian Squeeze, using mysql 5.1 and php  
5.3.3-7+squeeze3 with Suhosin-Patch.

I followed the install docs (because there is nothing to suggest  
different for an upgradeon the website).  And, since I couldn't find  
any information that said otherwise, I just left everything in  
/var/www/horde from my 3.3.8 install alone, figuring that pear would  
just dump on top of that, as the creators intended.

After updating horde, and pointing my browser to  
http://{mybox}.com/horde, I get: A fatal error has occurred
You must configure a DataTree backend to use Shares.

[line 47 of /var/www/horde/lib/Horde/Share/datatree.php]

on the left panel where navigation should be, and just a white screen  
where the interface should be.

My apache2/error.log has this in it:

[Thu Sep 22 19:34:30 2011] [error] [client 192.168.0.x] PHP  
Deprecated:  Assigning thereturn value of new by reference is  
deprecated in
/var/www/horde/lib/Horde/Share/datatree.php on line 81, referer:
https://mx2.mybox.com/horde/
[Thu Sep 22 19:34:30 2011] [error] [client 192.168.0.x] PHP  
Deprecated:  Assigning the return value of new by reference is  
deprecated in
/var/www/horde/lib/Horde/Share/datatree.php on line 99, referer:
https://mx2.mybox.com/horde/
[Thu Sep 22 19:34:30 2011] [error] [client 192.168.0.x] PHP  
Deprecated:  Assigning the return value of new by reference is  
deprecated in
/var/www/horde/lib/Horde/Share/datatree.php on line 123, referer:
https://mx2.mybox.com/horde/
[Thu Sep 22 19:34:30 2011] [error] [client 192.168.0.x] PHP  
Deprecated:  Assigning the return value of new by reference is  
deprecated in
/var/www/horde/lib/Horde/Share/datatree.php on line 211, referer:
https://mx2.mybox.com/horde/
[Thu Sep 22 19:34:30 2011] [error] [client 192.168.0.x] PHP  
Deprecated:  Assigning the return value of new by reference is  
deprecated in /var/www/horde/lib/Horde/Prefs.php on
line 847, referer: https://mx2.mybox.com/horde/
[Thu Sep 22 19:34:30 2011] [error] [client 192.168.0.x] PHP  
Deprecated:  Assigning the return value of new by reference is  
deprecated in
/var/www/horde/lib/Horde/Block/Collection.php on line 146, referer:
https://mx2.mybox.com/horde/

I don't know what is going on here... i could use a hand.


Thank you.

-Chris