5.1 errors (with phpBB)

[ConTractor]

After trying to upgrade, I had to delete all files on server and do a fresh install. Before I did this I installed phpBB.

All installations went fine, but now when I access the main PP site, I get:

Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /usr/www/virtual/MYUSERNAME/www.MYSITE.com/pp-inc.php on line 2876

Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /usr/www/virtual/MYUSERNAME/www.MYSITE.com/pp-inc.php on line 756

When I try to enter the admin area for PP, I get:
Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /usr/www/virtual/MYUSERNAME/www.MYSITE.com/pp-inc.php on line 2876

I use the same DB for both PP and phpBB (photo_)

The phpBB-board is running as it should.....

Any idea?

EDIT:
Whe trying to access with Opera I get:
Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /usr/www/virtual/MYUSERNAME/www.MYSITE.com/pp-inc.php on line 2876

Warning: Cannot modify header information - headers already sent by (output started at /usr/www/virtual/MYUSERNAME/www.MYSITE.com/pp-inc.php:2876) in /usr/www/virtual/MYUSERNAME/www.MYSITE.com/forums/phpbb2.php on line 220

Warning: Cannot modify header information - headers already sent by (output started at /usr/www/virtual/MYUSERNAME/www.MYSITE.com/pp-inc.php:2876) in /usr/www/virtual/MYUSERNAME/www.MYSITE.com/forums/phpbb2.php on line 221

[Chuck S]

Your usergroups table was not created

You can enter this in phpmyadmin make sure to add any prefix

CREATE TABLE usergroups (groupid int(5) NOT NULL auto_increment, groupname varchar(50) NOT NULL default '', cpaccess smallint(3) NOT NULL default '0', modaccess smallint(3) NOT NULL default '0', uploads smallint(3) NOT NULL default '1', comments smallint(3) NOT NULL default '1', diskspace int(10) default NULL, uploadsize int(10) default NULL, uplimit INT(5) DEFAULT '0' NOT NULL, editpho int(3) NOT NULL default '0', editposts int(3) NOT NULL default '0', useralbums int(3) NOT NULL default '0',reqmod INT(3) DEFAULT '0' NOT NULL, canassign INT(3) DEFAULT '0' NOT NULL, PRIMARY KEY (groupid)) TYPE=MyISAM;
INSERT INTO usergroups VALUES ('1','Anonymous','','','','','','',0,0,0,0,0,0);
INSERT INTO usergroups VALUES ('2','Admin',1,1,1,'','','',1,1,1,1,0,1);
INSERT INTO usergroups VALUES ('3','Regular Users','',1,1,'','','',1,1,0,1,0,0);