diff -up cups-1.4.2/backend/snmp.c.str3413 cups-1.4.2/backend/snmp.c
--- cups-1.4.2/backend/snmp.c.str3413	2009-01-14 22:40:58.000000000 +0000
+++ cups-1.4.2/backend/snmp.c	2009-12-03 10:01:27.933335209 +0000
@@ -999,7 +999,7 @@ read_snmp_response(int fd)		/* I - SNMP 
 		       DEVICE_PRODUCT, LexmarkProductOID2);
 	_cupsSNMPWrite(fd, &(packet.address), CUPS_SNMP_VERSION_1,
 	               packet.community, CUPS_ASN1_GET_REQUEST,
-		       DEVICE_URI, LexmarkDeviceIdOID);
+		       DEVICE_ID, LexmarkDeviceIdOID);
 	_cupsSNMPWrite(fd, &(packet.address), CUPS_SNMP_VERSION_1,
 	               packet.community, CUPS_ASN1_GET_REQUEST,
 		       DEVICE_PRODUCT, XeroxProductOID);
@@ -1064,7 +1064,19 @@ read_snmp_response(int fd)		/* I - SNMP 
 
 
 	  if (device->id)
+	  {
+	    if (strlen (device->id) >
+		strlen ((char *)packet.object_value.string.bytes))
+	    {
+	     /*
+	      * The Device ID we already saw was more complete.
+	      */
+
+	      break;
+	    }
+
 	    free(device->id);
+	  }
 
 	  device->id = strdup((char *)packet.object_value.string.bytes);
 
@@ -1107,7 +1119,8 @@ read_snmp_response(int fd)		/* I - SNMP 
 
     case DEVICE_URI :
 	if (device && packet.object_type == CUPS_ASN1_OCTET_STRING &&
-	    !device->uri)
+	    !device->uri &&
+	    (char *)packet.object_value.string.bytes[0] != '\0')
 	{
 	 /*
 	  * Update an existing cache entry...