Widgets not working

I’m using WP 2.2

The enabled plugins are
Akismet 2.0.2
All in One SEO Pack 0.6.2.1
Angsuman’s Translator Plugin Pro 4.0.2
cforms 4.7
Feedburner Feed Replacement 2.2
Google Sitemaps 2.7.1
Most Commented 1.02
Recent Comments 1.18
Recent Posts 1.07
TLA InLinks 1.0.9
WordPress Database Backup 1.8
wp-cache 2.1
WP-Forum 1.7.4

However, I doubt the plugins cause the problem, because I deactivated all of them and the widgets still didn’t work.

I’m using a customised theme for the site and the dynamic sidebar is called by the usual
<?php if ( function_exists('dynamic_sidebar') && dynamic_sidebar('SidebarLeft') ) : else : ?>

and the function.php has

if ( function_exists('register_sidebar') )
	register_sidebar(array(
		'name' => 'SidebarLeft',
		'before_widget' => '<div class="Links">',
		'after_widget' => '</div>',
		'before_title' => '<h2>',
		'after_title' => '</h2>',
	));

Similarly I have dynamic sidebars called SideBarRight and a FooterArea

Now when I go to Presentation->Widgets

I see the sidebars with the widgets in them, as well as the list of available widgets below. But I can’t drag and drop any widget around. If I click and drag it selects the text like a click drag would do on a normal page of text.