I just tried it in Chrome 17.0.963.78 and it works fine:
<script type="text/javascript">
var str="asd.sdf";
var arr = str.split(".");
document.write(arr);
document.write("<br />DONE<br />");
document.write(str.split(".") + "<br />");
</script>
Gave:
asd,sdf
DONE
asd,sdf
What am I doing that is different to you?