diff --git a/app/src/main/java/com/m2049r/xmrwallet/fragment/send/SendAddressWizardFragment.java b/app/src/main/java/com/m2049r/xmrwallet/fragment/send/SendAddressWizardFragment.java
index 190e956..38feb6a 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/fragment/send/SendAddressWizardFragment.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/fragment/send/SendAddressWizardFragment.java
@@ -183,6 +183,7 @@ public class SendAddressWizardFragment extends SendWizardFragment {
                     selectedCrypto = Crypto.XMR;
                     sendListener.setMode(SendFragment.Mode.XMR);
                 }
+                if (!Helper.ALLOW_SHIFT) return;
                 if ((selectedCrypto == null) && isEthAddress(address)) {
                     Timber.d("isEthAddress");
                     possibleCryptos.add(Crypto.ETH);
@@ -465,7 +466,8 @@ public class SendAddressWizardFragment extends SendWizardFragment {
                     possibleCryptos.add(barcodeData.asset);
                     selectedCrypto = barcodeData.asset;
                 }
-                updateCryptoButtons(false);
+                if (Helper.ALLOW_SHIFT)
+                    updateCryptoButtons(false);
                 if (checkAddress()) {
                     if (barcodeData.security == BarcodeData.Security.OA_NO_DNSSEC)
                         etAddress.setError(getString(R.string.send_address_no_dnssec));
diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/Helper.java b/app/src/main/java/com/m2049r/xmrwallet/util/Helper.java
index e093573..d53c84d 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/Helper.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/Helper.java
@@ -80,6 +80,7 @@ public class Helper {
     static public final String NOCRAZYPASS_FLAGFILE = ".nocrazypass";
 
     static public final String BASE_CRYPTO = Crypto.XMR.getSymbol();
+    static public final int XMR_DECIMALS = 12;
 
     static public final boolean SHOW_EXCHANGERATES = true;
     static public final boolean ALLOW_SHIFT = true;
@@ -159,11 +160,11 @@ public class Helper {
     }
 
     static public BigDecimal getDecimalAmount(long amount) {
-        return new BigDecimal(amount).scaleByPowerOfTen(-12);
+        return new BigDecimal(amount).scaleByPowerOfTen(-XMR_DECIMALS);
     }
 
     static public String getDisplayAmount(long amount) {
-        return getDisplayAmount(amount, 12);
+        return getDisplayAmount(amount, XMR_DECIMALS);
     }
 
     static public String getDisplayAmount(long amount, int maxDecimals) {
@@ -195,7 +196,7 @@ public class Helper {
     static public String getDisplayAmount(double amount) {
         // a Java bug does not strip zeros properly if the value is 0
         BigDecimal d = new BigDecimal(amount)
-                .setScale(12, BigDecimal.ROUND_HALF_UP)
+                .setScale(XMR_DECIMALS, BigDecimal.ROUND_HALF_UP)
                 .stripTrailingZeros();
         if (d.scale() < 1)
             d = d.setScale(1, BigDecimal.ROUND_UNNECESSARY);
diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/LegacyStorageHelper.java b/app/src/main/java/com/m2049r/xmrwallet/util/LegacyStorageHelper.java
index 9ccdf5c..68a1f6b 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/LegacyStorageHelper.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/LegacyStorageHelper.java
@@ -53,6 +53,7 @@ public class LegacyStorageHelper {
     public void migrate() {
         String addressPrefix = WalletManager.getInstance().addressPrefix();
         File[] wallets = srcDir.listFiles((dir, filename) -> filename.endsWith(".keys"));
+        if (wallets == null) return;
         for (File wallet : wallets) {
             final String walletName = wallet.getName().substring(0, wallet.getName().length() - ".keys".length());
             if (addressPrefix.indexOf(getAddress(walletName).charAt(0)) < 0) {
diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/Notice.java b/app/src/main/java/com/m2049r/xmrwallet/util/Notice.java
index 8e5c4df..673e37a 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/Notice.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/Notice.java
@@ -30,6 +30,7 @@ import androidx.fragment.app.FragmentManager;
 
 import com.m2049r.xmrwallet.R;
 import com.m2049r.xmrwallet.dialog.HelpFragment;
+import com.m2049r.xmrwallet.ledger.Ledger;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -52,12 +53,13 @@ public class Notice {
                                 R.string.help_xmrto,
                                 1)
                 );
-            notices.add(
-                    new Notice(NOTICE_SHOW_LEDGER,
-                            R.string.info_ledger_enabled,
-                            R.string.help_create_ledger,
-                            1)
-            );
+            if (Ledger.ENABLED)
+                notices.add(
+                        new Notice(NOTICE_SHOW_LEDGER,
+                                R.string.info_ledger_enabled,
+                                R.string.help_create_ledger,
+                                1)
+                );
         }
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/RestoreHeight.java b/app/src/main/java/com/m2049r/xmrwallet/util/RestoreHeight.java
index f0177d3..1619bf2 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/RestoreHeight.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/RestoreHeight.java
@@ -26,6 +26,8 @@ import java.util.TimeZone;
 import java.util.concurrent.TimeUnit;
 
 public class RestoreHeight {
+    static final int DIFFICULTY_TARGET = 120; // seconds
+
     static private RestoreHeight Singleton = null;
 
     static public RestoreHeight getInstance() {
@@ -190,7 +192,7 @@ public class RestoreHeight {
         } else {
             long days = TimeUnit.DAYS.convert(query.getTimeInMillis() - prevTime,
                     TimeUnit.MILLISECONDS);
-            height = Math.round(prevBc + 1.0 * days * (24 * 60 / 2));
+            height = Math.round(prevBc + 1.0 * days * (24f * 60 * 60 / DIFFICULTY_TARGET));
         }
         return height;
     }