diff --git a/libraries/DataFlash/DataFlash.h b/libraries/DataFlash/DataFlash.h
index 653a9097ac..8c31ab439f 100644
--- a/libraries/DataFlash/DataFlash.h
+++ b/libraries/DataFlash/DataFlash.h
@@ -13,13 +13,6 @@
 #include <AP_AHRS.h>
 #include <stdint.h>
 
-// the last page holds the log format in first 4 bytes. Please change
-// this if (and only if!) the low level format changes
-#define DF_LOGGING_FORMAT    0x28122013
-
-// we use an invalie logging format to test the chip erase
-#define DF_LOGGING_FORMAT_INVALID   0x28122012
-
 class DataFlash_Class
 {
 public:
diff --git a/libraries/DataFlash/DataFlash_Block.cpp b/libraries/DataFlash/DataFlash_Block.cpp
index 4f31a34542..b3c7a5e2e2 100644
--- a/libraries/DataFlash/DataFlash_Block.cpp
+++ b/libraries/DataFlash/DataFlash_Block.cpp
@@ -8,6 +8,10 @@
 
 extern AP_HAL::HAL& hal;
 
+// the last page holds the log format in first 4 bytes. Please change
+// this if (and only if!) the low level format changes
+#define DF_LOGGING_FORMAT    0x28122013
+
 // *** DATAFLASH PUBLIC FUNCTIONS ***
 void DataFlash_Block::StartWrite(uint16_t PageAdr)
 {
@@ -149,17 +153,19 @@ uint16_t DataFlash_Block::GetFilePage()
 
 void DataFlash_Block::EraseAll()
 {
-    for(uint16_t j = 1; j <= (df_NumPages+1)/8; j++) {
+    for (uint16_t j = 1; j <= (df_NumPages+1)/8; j++) {
         BlockErase(j);
         if (j%6 == 0) {
             hal.scheduler->delay(6);
         }
     }
     // write the logging format in the last page
+    hal.scheduler->delay(100);
     StartWrite(df_NumPages+1);
     uint32_t version = DF_LOGGING_FORMAT;
     WriteBlock(&version, sizeof(version));
     FinishWrite();
+    hal.scheduler->delay(100);
 }
 
 /*
@@ -172,5 +178,3 @@ bool DataFlash_Block::NeedErase(void)
     ReadBlock(&version, sizeof(version));
     return version != DF_LOGGING_FORMAT;
 }
-
-
diff --git a/libraries/DataFlash/DataFlash_Block.h b/libraries/DataFlash/DataFlash_Block.h
index a6432d6bbf..b25f45242d 100644
--- a/libraries/DataFlash/DataFlash_Block.h
+++ b/libraries/DataFlash/DataFlash_Block.h
@@ -9,13 +9,6 @@
 
 #include <stdint.h>
 
-// the last page holds the log format in first 4 bytes. Please change
-// this if (and only if!) the low level format changes
-#define DF_LOGGING_FORMAT    0x28122013
-
-// we use an invalie logging format to test the chip erase
-#define DF_LOGGING_FORMAT_INVALID   0x28122012
-
 class DataFlash_Block : public DataFlash_Class
 {
 public: