Found this while working on a new install of freePBX 2.10 (on a Raspberry PI).
While recordings tries to connect to the CDR database, the following error is logged;
"PHP Fatal error: Cannot redeclare class DB_mysql in /usr/share/php/DB/mysql.php on line 48"
Fixed by downgrading the pear DB package to 1.7.13.
pear uninstall DB
pear install DB-1.7.13