diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 86b9b093..79ae0d5d 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,3 +1,7 @@
+0.3.3pre [2013-05-30]
+---------------------
+ - added debug info to rsasign-1.2.js
+
 0.3.2 [2013-05-30]
 ------------------
  - fixed regex pattern for SDID, Selector and local_part
diff --git a/chrome/content/dkim.js b/chrome/content/dkim.js
index 91c86bf2..7b8d575d 100644
--- a/chrome/content/dkim.js
+++ b/chrome/content/dkim.js
@@ -4,7 +4,7 @@
  * Verifies the DKIM-Signatures as specified in RFC 6376
  * http://tools.ietf.org/html/rfc6376
  *
- * version: 0.3.2 (30 May 2013)
+ * version: 0.3.3pre (30 May 2013)
  *
  * Copyright (c) 2013 Philippe Lieser
  *
@@ -912,7 +912,7 @@ DKIM_Verifier.DKIMVerifier = (function() {
 			var isValid = rsa.verifyString(headerHashInput, DKIM_Verifier.b64tohex(msg.DKIMSignature.b));
 			
 			if (!isValid) {
-				throw new DKIM_SigError(DKIM_STRINGS.DKIM_SIGERROR_CORRUPT_B);
+				throw new DKIM_SigError(DKIM_STRINGS.DKIM_SIGERROR_BADSIG);
 			}
 			
 			// show result
@@ -1113,7 +1113,12 @@ var that = {
 				Components.utils.reportError(e+"\n"+e.stack);
 			}
 		}
-	}
+	},
+	
+	/*
+	 * make function dkimDebugMsg(message) public
+	 */
+	dkimDebugMsg : dkimDebugMsg
 };
 return that;
 }()); // the parens here cause the anonymous function to execute and return
diff --git a/chrome/content/rsasign-1.2.js b/chrome/content/rsasign-1.2.js
index a2d12b97..b3744c61 100644
--- a/chrome/content/rsasign-1.2.js
+++ b/chrome/content/rsasign-1.2.js
@@ -1,3 +1,11 @@
+/*
+ * Original version 1.2.1 (08 May 2013)
+ * Modified by Philippe Lieser for "DKIM Verifier" version 0.3.3
+ *
+ * Modifications:
+ *  - added debug info to _rsasign_verifyString
+ */
+
 /*! rsasign-1.2.js (c) 2012 Kenji Urushima | kjur.github.com/jsrsasign/license
  */
 //
@@ -267,14 +275,26 @@ function _rsasign_verifyHexSignatureForMessage(hSig, sMsg) {
  */
 function _rsasign_verifyString(sMsg, hSig) {
     hSig = hSig.replace(_RE_HEXDECONLY, '');
-    if (hSig.length != this.n.bitLength() / 4) return 0;
+    // if (hSig.length != this.n.bitLength() / 4) return 0;
+    if (hSig.length != this.n.bitLength() / 4) {
+        DKIMVerifier.dkimDebugMsg("rsasign: hSig has wrong length");
+        return 0;
+        // throw new Error("rsasign Error: hSig has wrong length");
+    }
     hSig = hSig.replace(/[ \n]+/g, "");
     var biSig = parseBigInt(hSig, 16);
     var biDecryptedSig = this.doPublic(biSig);
     var hDigestInfo = biDecryptedSig.toString(16).replace(/^1f+00/, '');
     var digestInfoAry = _rsasign_getAlgNameAndHashFromHexDisgestInfo(hDigestInfo);
   
-    if (digestInfoAry.length == 0) return false;
+    // if (digestInfoAry.length == 0) return false;
+    if (digestInfoAry.length == 0) {
+        DKIMVerifier.dkimDebugMsg("rsasign: biDecryptedSig (hex): " + biDecryptedSig.toString(16));
+        DKIMVerifier.dkimDebugMsg("rsasign: n (hex): " + this.n.toString(16));
+        DKIMVerifier.dkimDebugMsg("rsasign: e: " + this.e);
+        DKIMVerifier.dkimDebugMsg("rsasign: digestInfoAry.length == 0");
+        return false;
+    }
     var algName = digestInfoAry[0];
     var diHashValue = digestInfoAry[1];
     var ff = _RSASIGN_HASHHEXFUNC[algName];
diff --git a/chrome/locale/en-US/dkim.js b/chrome/locale/en-US/dkim.js
index 0ce00245..06bccdb5 100644
--- a/chrome/locale/en-US/dkim.js
+++ b/chrome/locale/en-US/dkim.js
@@ -21,7 +21,8 @@ DKIM_STRINGS.DKIM_SIGERROR_MISSING_V		= "DKIM version missing";
 DKIM_STRINGS.DKIM_SIGERROR_MISSING_A		= "Missing signature algorithm";
 DKIM_STRINGS.DKIM_SIGERROR_UNKNOWN_A		= "Unsupported Signature algorithm";
 DKIM_STRINGS.DKIM_SIGERROR_MISSING_B		= "Missing signature";
-DKIM_STRINGS.DKIM_SIGERROR_CORRUPT_B		= "Signature wrong";
+// DKIM_STRINGS.DKIM_SIGERROR_CORRUPT_B		= "Signature wrong";
+DKIM_STRINGS.DKIM_SIGERROR_BADSIG			= "Signature wrong";
 DKIM_STRINGS.DKIM_SIGERROR_MISSING_BH		= "Missing body hash";
 DKIM_STRINGS.DKIM_SIGERROR_CORRUPT_BH		= "Wrong body hash";
 DKIM_STRINGS.DKIM_SIGERROR_UNKNOWN_C_H		= "Unsupported canonicalization algorithm for header";
diff --git a/install.rdf b/install.rdf
index 537559d5..f6535fce 100644
--- a/install.rdf
+++ b/install.rdf
@@ -10,7 +10,7 @@
 		<em:name>DKIM Verifier</em:name>
 		<em:description>Verifies the DKIM-Signature of an e-mail.</em:description>
 
-		<em:version>0.3.2</em:version>
+		<em:version>0.3.3pre</em:version>
 
 		<em:creator>Philippe Lieser</em:creator>