not tracking error

I'm getting this error, must be something simple but I'm not sure where to look.

[Wed May 08 00:45:37 2013] [error] [client x.x.x.x] script '/path/to/piwikpiwik.php' not found or unable to stat, referer: http://x.x.x/index.php?/albums/5

Any help would be very much appreciated.