This does fix it. But it has a major flaw. If you do this change, and switch language while editing an unsaved post, you will lose your changes. This was reported elsewhere.
As you can see in the link above, I posted an alternative solution, which is copied below…
Instead of removing the js completely, I tried changing the js that it calls, giving it a longer timeout period. I think the issue is that sometimes this chunk of qTranslate js is getting called too early.
Here is qtranslate_javascript.php from line 217. You need to change the number at the end of this, from 250. When I changed it to 500, it seemed to fix the issue.
$q_config['js']['qtrans_disable_old_editor'] = "
var waitForTinyMCE = window.setInterval(function() {
if(typeof(tinyMCE) !== 'undefined' && typeof(tinyMCE.get2) == 'function' && tinyMCE.get2('content')!=undefined) {
content=jQuery('#content').val();
tinyMCE.get2('content').remove();
jQuery('#content').val(content);
window.clearInterval(waitForTinyMCE);
}
}, 500); // HACK: used to be 250
";
So far it is working for me. Please let us know if this fixes it for you.