diff --git a/phpBB/adm/style/install_update_diff.html b/phpBB/adm/style/install_update_diff.html
index efbe1d045c..d794c5c516 100644
--- a/phpBB/adm/style/install_update_diff.html
+++ b/phpBB/adm/style/install_update_diff.html
@@ -28,6 +28,9 @@ function resize_panel()
 		//whatever IE needs to do this
 	}	
 }
+
+window.onresize = resize_panel;
+
 // ]]>
 </script>
 
@@ -48,10 +51,7 @@ function resize_panel()
 
 <!-- IF DIFF_MODE neq 'side_by_side' and DIFF_MODE neq 'raw' -->
 div#codepanel {
-	overflow: auto;
 	width: 100%;
-	height: 350px;
-	display: inline-block;
 }
 <!-- ELSE -->
 div#codepanel {	
@@ -59,12 +59,22 @@ div#codepanel {
 }
 <!-- ENDIF -->
 
+<!-- IF DIFF_MODE neq 'unified' and DIFF_MODE neq 'side_by_side'  -->
+div#diff_content pre {
+	overflow: auto;
+	height: 414px;
+	width: 100% !important;
+}
+<!-- ENDIF -->
+
 <!-- IF not S_DIFF_NEW_FILE -->
 /**
 * Unified Diff
 */
 .file {
 	line-height: .7em;
+	overflow: auto;
+	height: 414px;
 }
 
 .diff {
@@ -203,9 +213,8 @@ table.hrdiff caption span {
 
 </head>
 
-
 <!-- IF DIFF_MODE neq 'side_by_side' and DIFF_MODE neq 'raw' -->
-<body onresize="resize_panel();" onload="resize_panel();">
+<body onload="resize_panel();">
 <!-- ELSE -->
 <body>
 <!-- ENDIF -->
@@ -220,7 +229,7 @@ table.hrdiff caption span {
 <!-- ENDIF -->
 <!-- IF not S_DIFF_NEW_FILE -->
 		<p id="skip"><a href="#acp">{L_SKIP}</a></p>
-		<form method="post">
+		<form method="post" action="">
 		<fieldset class="quick">
 			<label for="diff_mode">{L_SELECT_DIFF_MODE}:</label>
 			<select name="diff_mode" id="diff_mode">{S_DIFF_MODE_OPTIONS}</select>
diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index d72e75b009..2cc0b05e38 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -264,7 +264,7 @@
 		<li>[Fix] Changed the success message when requesting a new password to be more accurate. (Bug #41405)</li>
 		<li>[Fix] Add missing anti-abuse email headers to acp_inactive.php and ucp_resend.php.</li>
 		<li>[Fix] Only remind users in the correct inactive states depending on the board account activation level.</li>
-		<li>[Fix] Various XHTML mistakes in prosilver, subsilver2 and the ACP. (Bugs #41745, #42265 - Patch by nickvergessen, #38465, #43015)</li>
+		<li>[Fix] Various XHTML mistakes in prosilver, subsilver2 and the ACP. (Bugs #41745, #42265 - Patch by nickvergessen, #38465, #43015, #46585 - Patch by Raimon)</li>
 		<li>[Fix] Log password changes via password reset function. (Bug #41365)</li>
 		<li>[Fix] Poll, negative durations generate error (Bug #41295 - Patch by TerraFrost)</li>
 		<li>[Fix] Visibility of custom field on registration is incorrectly controlled by setting &quot;display&quot; (Bug #41385 - Patch by Eelke and fade2gray)</li>
diff --git a/phpBB/includes/diff/renderer.php b/phpBB/includes/diff/renderer.php
index 02fb6ccc37..5cb1b6ada9 100644
--- a/phpBB/includes/diff/renderer.php
+++ b/phpBB/includes/diff/renderer.php
@@ -536,7 +536,7 @@ class diff_renderer_raw extends diff_renderer
 	*/
 	function get_diff_content($diff)
 	{
-		return '<textarea style="height: 290px;" class="full">' . htmlspecialchars($this->render($diff)) . '</textarea>';
+		return '<textarea style="height: 290px;" rows="15" cols="76" class="full">' . htmlspecialchars($this->render($diff)) . '</textarea>';
 	}
 
 	function _block_header($xbeg, $xlen, $ybeg, $ylen)
