Index: wp-includes/formatting.php
===================================================================
--- wp-includes/formatting.php	(revision 11262)
+++ wp-includes/formatting.php	(working copy)
@@ -134,7 +134,7 @@
 	foreach ( $pees as $tinkle )
 		$pee .= '<p>' . trim($tinkle, "\n") . "</p>\n";
 	$pee = preg_replace('|<p>\s*</p>|', '', $pee); // under certain strange conditions it could create a P of entirely whitespace
-	$pee = preg_replace('!<p>([^<]+)</(div|address|form)>!', "<p>$1</p></$2>", $pee);
+	$pee = preg_replace('#<p>\s*?(?!</)(\S.*)(</(?:address|div|form)[^>]*>)#', "<p>$1</p>$2", $pee); 
 	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee); // don't pee all over a tag
 	$pee = preg_replace("|<p>(<li.+?)</p>|", "$1", $pee); // problem with nested lists
 	$pee = preg_replace('|<p><blockquote([^>]*)>|i', "<blockquote$1><p>", $pee);