Non excisting cache files

When saying words to Mai she automatically loads cache files based on the first 3 letters of the word. However for some combinations (in this case 'hoi') there are no cache files. This results in an error:

Jij: hoi
Mai: <br /> <b>Warning</b>: require(/home/sprenkels/mai/cache/opentaal/opentaalCache_hoi.php) [<a href='function.require'>function.require</a>]: failed to open stream: Bestand of map bestaat niet in <b>/home/sprenkels/mai/library/Mai/Cache/Words.php</b> on line <b>199</b><br /> <br /> <b>Fatal error</b>: require() [<a href='function.require'>function.require</a>]: Failed opening required '/home/sprenkels/mai/cache/opentaal/opentaalCache_hoi.php' (include_path='.:.:/opt/lampp/lib/php:/home/sprenkels/mai/library:/home/sprenkels/mai/application/models') in <b>/home/sprenkels/mai/library/Mai/Cache/Words.php</b> on line <b>199</b><br />