diff --git a/chrome/content/overlay.js b/chrome/content/overlay.js
index 473a8c985..12c799ab1 100755
--- a/chrome/content/overlay.js
+++ b/chrome/content/overlay.js
@@ -295,11 +295,11 @@ wappalyzer =
 
 	urlChange:
 	{
-		QueryInterface: function( aIID )
+		QueryInterface: function(iid)
 		{
-			if ( aIID.equals(Components.interfaces.nsIWebProgressListener)   ||
-			     aIID.equals(Components.interfaces.nsISupportsWeakReference) ||
-			     aIID.equals(Components.interfaces.nsISupports) )
+			if ( iid.equals(Components.interfaces.nsIWebProgressListener)   ||
+			     iid.equals(Components.interfaces.nsISupportsWeakReference) ||
+			     iid.equals(Components.interfaces.nsISupports) )
 			{
 				return this;
 			}
@@ -307,14 +307,21 @@ wappalyzer =
 			throw Components.results.NS_NOINTERFACE;
 		},
 
-		onLocationChange: function(aProgress, aRequest, aURI)
+		onLocationChange: function(progress, request, url)
 		{
-			if ( aURI.spec != wappalyzer.prevUrl )
+			if ( !url )
 			{
-				wappalyzer.prevUrl = aURI.spec;
+				wappalyzer.prevUrl = '';
+
+				return;
+			}
+
+			if ( url.spec != wappalyzer.prevUrl )
+			{
+				wappalyzer.prevUrl = url.spec;
 				
-				// A tiny pauze to let the page load, otherwise some elements are displayed incorrectly
-				setTimeout(wappalyzer.onUrlChange(), 50);
+				// A tiny pauze to let the page load, otherwise some elements are displayed incorrectly in FF 3.5
+				setTimeout('wappalyzer.onUrlChange()', 50);
 			}
 		},
 
@@ -357,7 +364,12 @@ wappalyzer =
 			// Scan HTML for patterns
 			var html = doc.getElementsByTagName('html')[0].innerHTML;
 
-			if ( html && html.length < 500000 ) // Skip long pages
+			if ( html.length > 50000 ) // Prevent large documents from slowing things down
+			{
+				html = html.substring(0, 25000) + html.substring(html.length - 25000, html.length);
+			}
+			
+			if ( html )
 			{
 				for ( i = 0; i < wappalyzer.app.length; i ++ )
 				{
diff --git a/install.rdf b/install.rdf
index 1931b73ae..ac983ba36 100755
--- a/install.rdf
+++ b/install.rdf
@@ -5,7 +5,7 @@
 <RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#">
   <Description about="urn:mozilla:install-manifest">
     <em:id>wappalyzer@crunchlabz.com</em:id>
-    <em:version>1.7.3</em:version>
+    <em:version>1.7.4</em:version>
     <em:type>2</em:type>
 
     <em:targetApplication>
@@ -17,9 +17,9 @@
     </em:targetApplication>
 
 	<em:optionsURL>chrome://wappalyzer/content/options.xul</em:optionsURL>
-    
+
 	<em:name>Wappalyzer</em:name>
-    <em:description>Detects which software is used on the page you're at.</em:description>
+    <em:description>Wappalyzer identifies software used on the websites you visit.</em:description>
 	<em:iconURL>chrome://wappalyzer/skin/icon32x32.png</em:iconURL>
     <em:author>ElbertF</em:author>
     <em:creator>ElbertF</em:creator>