Search > By Genre > Style = World causes " Uninitialized string offset" error

Verified this occurs in Mac OSX 10.10.5 Chrome and Safari

* Open http://www.wikiloops.com/tracks/track-finder.php
* Click Style
* Choose World (doesn't appear to occur with other styles)
* Observe list of errors in the trio backing tracks section such as:

Notice: Uninitialized string offset: 0 in /www/htdocs/v130977/www/htdocs/v130977/files/includes/loopheap_include.php on line 356


Screenshot: https://www.dropbox.com/s/o8ijshllh89gzxb/Screen%20Shot%202016-04-28%20at%2012.24.44%20PM.png?dl=0

thanks for the hint - will be fixed after a page refresh :)