Error with DataObject

Hi, I'm in the process of building a website using PEAR and DataObject and to-date its been a very positive experience, I can see some really interesting design patterns becoming available. I have just been toying with the validation method. My view is to include a range of business logic in the relevant classes, but the forst time I tried to use it I get the following message <warning> Warning: validate(Validate.php) [function.validate]: failed to create stream: No such file or directory in /usr/share/pear/DB/DataObject.php on line 1623 Fatal error: validate() [function.validate]: Failed opening required 'Validate.php' (include_path='.:./conf:/usr/local/lib/php:/php/includes:/usr/share/pear:/www/include:/www/include/Smarty') in "/usr/share/pear/DB/DataObject.php" on line 1623 </warning> (I put the warning tags on) Anyone know why this would occur? Thanks Barry