diff --git a/build/shared/revisions.txt b/build/shared/revisions.txt
index 53f0e7de7..5573bf458 100644
--- a/build/shared/revisions.txt
+++ b/build/shared/revisions.txt
@@ -5,6 +5,7 @@ ARDUINO 1.5.5 BETA
 * avr: Fixed buffer overflow in File::doBuffer() (dreggy)
 * avr: Fixed timeout in Bridge::transfer()
 * sam: Fixed SPI initialization (when using extended API and multiple CS)
+* avr: Fixed behavior of EthernetClient::flush()
 
 ARDUINO 1.5.4 BETA 2013.09.10
 
diff --git a/libraries/Ethernet/arch/avr/utility/socket.cpp b/libraries/Ethernet/arch/avr/utility/socket.cpp
index 154ba9895..5332981d2 100644
--- a/libraries/Ethernet/arch/avr/utility/socket.cpp
+++ b/libraries/Ethernet/arch/avr/utility/socket.cpp
@@ -256,7 +256,7 @@ uint16_t recvfrom(SOCKET s, uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t
     switch (W5100.readSnMR(s) & 0x07)
     {
     case SnMR::UDP :
-      W5100.read_data(s, (uint8_t *)ptr, head, 0x08);
+      W5100.read_data(s, ptr, head, 0x08);
       ptr += 8;
       // read peer's IP address, port number.
       addr[0] = head[0];
@@ -268,14 +268,14 @@ uint16_t recvfrom(SOCKET s, uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t
       data_len = head[6];
       data_len = (data_len << 8) + head[7];
 
-      W5100.read_data(s, (uint8_t *)ptr, buf, data_len); // data copy.
+      W5100.read_data(s, ptr, buf, data_len); // data copy.
       ptr += data_len;
 
       W5100.writeSnRX_RD(s, ptr);
       break;
 
     case SnMR::IPRAW :
-      W5100.read_data(s, (uint8_t *)ptr, head, 0x06);
+      W5100.read_data(s, ptr, head, 0x06);
       ptr += 6;
 
       addr[0] = head[0];
@@ -285,19 +285,19 @@ uint16_t recvfrom(SOCKET s, uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t
       data_len = head[4];
       data_len = (data_len << 8) + head[5];
 
-      W5100.read_data(s, (uint8_t *)ptr, buf, data_len); // data copy.
+      W5100.read_data(s, ptr, buf, data_len); // data copy.
       ptr += data_len;
 
       W5100.writeSnRX_RD(s, ptr);
       break;
 
     case SnMR::MACRAW:
-      W5100.read_data(s,(uint8_t*)ptr,head,2);
+      W5100.read_data(s, ptr, head, 2);
       ptr+=2;
       data_len = head[0];
       data_len = (data_len<<8) + head[1] - 2;
 
-      W5100.read_data(s,(uint8_t*) ptr,buf,data_len);
+      W5100.read_data(s, ptr, buf, data_len);
       ptr += data_len;
       W5100.writeSnRX_RD(s, ptr);
       break;
@@ -310,6 +310,12 @@ uint16_t recvfrom(SOCKET s, uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t
   return data_len;
 }
 
+/**
+ * @brief	Wait for buffered transmission to complete.
+ */
+void flush(SOCKET s) {
+  // TODO
+}
 
 uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len)
 {
diff --git a/libraries/Ethernet/arch/avr/utility/w5100.cpp b/libraries/Ethernet/arch/avr/utility/w5100.cpp
index ad09b2251..5f8bdc850 100644
--- a/libraries/Ethernet/arch/avr/utility/w5100.cpp
+++ b/libraries/Ethernet/arch/avr/utility/w5100.cpp
@@ -98,7 +98,7 @@ void W5100Class::recv_data_processing(SOCKET s, uint8_t *data, uint16_t len, uin
 {
   uint16_t ptr;
   ptr = readSnRX_RD(s);
-  read_data(s, (uint8_t *)ptr, data, len);
+  read_data(s, ptr, data, len);
   if (!peek)
   {
     ptr += len;
@@ -106,13 +106,13 @@ void W5100Class::recv_data_processing(SOCKET s, uint8_t *data, uint16_t len, uin
   }
 }
 
-void W5100Class::read_data(SOCKET s, volatile uint8_t *src, volatile uint8_t *dst, uint16_t len)
+void W5100Class::read_data(SOCKET s, volatile uint16_t src, volatile uint8_t *dst, uint16_t len)
 {
   uint16_t size;
   uint16_t src_mask;
   uint16_t src_ptr;
 
-  src_mask = (uint16_t)src & RMASK;
+  src_mask = src & RMASK;
   src_ptr = RBASE[s] + src_mask;
 
   if( (src_mask + len) > RSIZE ) 
diff --git a/libraries/Ethernet/arch/avr/utility/w5100.h b/libraries/Ethernet/arch/avr/utility/w5100.h
index 8dccd9f29..f5644833e 100644
--- a/libraries/Ethernet/arch/avr/utility/w5100.h
+++ b/libraries/Ethernet/arch/avr/utility/w5100.h
@@ -138,7 +138,7 @@ public:
    * the data from Receive buffer. Here also take care of the condition while it exceed
    * the Rx memory uper-bound of socket.
    */
-  void read_data(SOCKET s, volatile uint8_t * src, volatile uint8_t * dst, uint16_t len);
+  void read_data(SOCKET s, volatile uint16_t src, volatile uint8_t * dst, uint16_t len);
   
   /**
    * @brief	 This function is being called by send() and sendto() function also. 
diff --git a/libraries/Ethernet/arch/sam/utility/socket.cpp b/libraries/Ethernet/arch/sam/utility/socket.cpp
index a9afb761c..5332981d2 100644
--- a/libraries/Ethernet/arch/sam/utility/socket.cpp
+++ b/libraries/Ethernet/arch/sam/utility/socket.cpp
@@ -310,6 +310,12 @@ uint16_t recvfrom(SOCKET s, uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t
   return data_len;
 }
 
+/**
+ * @brief	Wait for buffered transmission to complete.
+ */
+void flush(SOCKET s) {
+  // TODO
+}
 
 uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len)
 {
diff --git a/libraries/Ethernet/src/EthernetClient.cpp b/libraries/Ethernet/src/EthernetClient.cpp
index b5911c5ee..3a88d15f8 100644
--- a/libraries/Ethernet/src/EthernetClient.cpp
+++ b/libraries/Ethernet/src/EthernetClient.cpp
@@ -120,8 +120,7 @@ int EthernetClient::peek() {
 }
 
 void EthernetClient::flush() {
-  while (available())
-    read();
+  ::flush(_sock);
 }
 
 void EthernetClient::stop() {
diff --git a/libraries/Ethernet/src/utility/socket.h b/libraries/Ethernet/src/utility/socket.h
index 17f89c7af..682e84709 100644
--- a/libraries/Ethernet/src/utility/socket.h
+++ b/libraries/Ethernet/src/utility/socket.h
@@ -13,6 +13,7 @@ extern int16_t recv(SOCKET s, uint8_t * buf, int16_t len);	// Receive data (TCP)
 extern uint16_t peek(SOCKET s, uint8_t *buf);
 extern uint16_t sendto(SOCKET s, const uint8_t * buf, uint16_t len, uint8_t * addr, uint16_t port); // Send data (UDP/IP RAW)
 extern uint16_t recvfrom(SOCKET s, uint8_t * buf, uint16_t len, uint8_t * addr, uint16_t *port); // Receive data (UDP/IP RAW)
+extern void flush(SOCKET s); // Wait for transmission to complete
 
 extern uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len);