LESS 1.3.3, watch mode hogging a lot of CPU in esp

I was using an older version of less (1.2.1) by accident and when I updated the .js to the most recent version (1.3.3) it seems that Espresso, my html/css editor, now takes 40% cpu and up to 90% when in development/watch mode. I've tried other versions and it seems like it happens with 1.3.1+. I've tried different variations of the watch mode and even disabling it completely and it's still using 40-50% cpu. I basically can't work with it now.

edit: It seems like it's mostly being caused by watch mode, which I highly depend on :(

This is what my site head looks like. Any suggestions would be appreciated as I do not understand js at all.

<!doctype html>
<html>

<head>

<meta charset="utf-8"/>

<title>Article Sample</title>

<meta name="viewport" content="width=device-width, initial-scale=1"/>
<!-- Adding "maximum-scale=1" fixes the Mobile Safari auto-zoom bug: http://filamentgroup.com/examples/iosScaleBug/ -->


<!-- Link directly to LESS stylesheet first -->
<link rel="stylesheet/less" href="style/default.less" type="text/css" media="screen" />
<link rel="stylesheet/less" href="style/tablet.less" type="text/css" media="screen" />
<link rel="stylesheet/less" href="style/mobile.less" type="text/css" media="screen" />
<link rel="stylesheet/less" href="style/wide-mobile.less" type="text/css" media="screen" />

<!-- Then link to LESS, and enable development watch mode -->
<script src="js/less-1.3.3.js" type="text/javascript"></script>
<script type="text/javascript" charset="utf-8">
    less.env = "development";
    less.watch();
</script>
<!-- Voilà! Instant LESS previews in Espresso -->

<!--[if lt IE 9]>
<script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->

</head>

I think it is better to precompile first and then make the site read the already-compiled .css instead.

You can use Koala app for precompiling the less file or you can use grunt too, and get rid of the less.js.