first time log in…"warning" and "fatal error"

Just completed install and config. everything went as usual then when prompted to log in with my just created un and pw and it brings me to a screen with this message:

“Warning: require_once(/data/22/2/138/37/2138037/user/2346543/htdocs/cm/wp-admin/custom-background.php) [function.require-once]: failed to open stream: No such file or directory in /data/22/2/138/37/2138037/user/2346543/htdocs/cm/wp-includes/theme.php on line 1617

Fatal error: require_once() [function.require]: Failed opening required ‘/data/22/2/138/37/2138037/user/2346543/htdocs/cm/wp-admin/custom-background.php’ (include_path=’.:/usr/services/vux/lib/php’) in /data/22/2/138/37/2138037/user/2346543/htdocs/cm/wp-includes/theme.php on line 1617″

I’m sure this is an easy thing to diagnose for someone but not me!

Thanks in advance.