Index: wp-admin/includes/plugin-install.php
===================================================================
--- wp-admin/includes/plugin-install.php	(revision 10356)
+++ wp-admin/includes/plugin-install.php	(working copy)
@@ -155,7 +155,9 @@
 								'name' => $tag['name'],
 								'id' => sanitize_title_with_dashes($tag['name']),
 								'count' => $tag['count'] );
+	echo '<p>';
 	echo wp_generate_tag_cloud($tags, array( 'single_text' => __('%d plugin'), 'multiple_text' => __('%d plugins') ) );
+	echo '</p><br class="clear" />';
 }
 
 /**
@@ -505,10 +507,12 @@
 	</div>
 	<div id="section-holder" class="wrap">
 	<?php
-		if ( version_compare($GLOBALS['wp_version'], $api->tested, '>') )
+		if ( !empty($api->tested) && version_compare( substr($GLOBALS['wp_version'], 0, strlen($api->tested)), $api->tested, '>') )
 			echo '<div class="updated"><p>' . __('<strong>Warning:</strong> This plugin has <strong>not been tested</strong> with your current version of WordPress.') . '</p></div>';
-		else if ( version_compare($GLOBALS['wp_version'], $api->requires, '<') )
-			echo '<div class="updated"><p>' . __('<strong>Warning:</strong> This plugin has not been marked as <strong>compatible</strong> with your version of WordPress.') . '</p></div>';
+
+		else if ( !empty($api->requires) && version_compare( substr($GLOBALS['wp_version'], 0, strlen($api->requires)), $api->requires, '<') )
+			echo '<div class="updated"><p>' . __('<strong>Warning:</strong> This plugin has <strong>not been marked as compatible</strong> with your version of WordPress.') . '</p></div>';
+
 		foreach ( (array)$api->sections as $section_name => $content ) {
 			$title = $section_name;
 			$title[0] = strtoupper($title[0]);