My b2evolution Version: Not Entered

I'm running version 2.4.2 of b2evolution

I get this on the top of all the sample blogs and my admin panel and

Notice: Only variable references should be returned by reference in /home/www/biochicken.info/inc/_core/model/dataobjects/_dataobjectcache.class.php on line 158

I checked the actual code and it looks like;

// Get changed value (we use eval() to allow constructs like $loop_dbchange['value'] = 'Group->get(\'ID\')'):
eval( '$loop_value = $this->'.$loop_dbchange['value'].';' );

Though Looking at the sample blogs (biochicken.info/blog2.php) There are alot of these errors in various places in the dataobjectcache files.

Any Help would be greatly appreciated. Thank you.