[horde] horde configuration error

[george at tiedemannglobe.com]

I have just installed horde. Then i configured it in the  
administration setup menu , but when i click generate configurations i  
get the following error. can some one please help

Warning: DataTree_sql::_connect(DB.php) [function.-connect]: failed to  
open stream: No such file or directory in  
/home/tiedeman/public_html/tiedemannglobe/Test/lib/Horde/DataTree/sql.php on  
line 1624

Fatal error: DataTree_sql::_connect() [function.require]: Failed  
opening required 'DB.php'  
(include_path='/public_html/tiedemannglobe/Test/lib/PEAR') in  
/home/tiedeman/public_html/tiedemannglobe/Test/lib/Horde/DataTree/sql.php on  
line 1624