diff --git a/src/base58.cpp b/src/base58.cpp
index 6df2dabc6..ee8b40541 100644
--- a/src/base58.cpp
+++ b/src/base58.cpp
@@ -255,6 +255,23 @@ CTxDestination DecodeDestination(const std::string &str, const CChainParams &par
 }
 } // namespace
 
+namespace
+{
+class CBitcoinAddressVisitor : public boost::static_visitor<bool>
+{
+private:
+    CBitcoinAddress* addr;
+
+public:
+    CBitcoinAddressVisitor(CBitcoinAddress* addrIn) : addr(addrIn) {}
+
+    bool operator()(const CKeyID& id) const { return addr->Set(id); }
+    bool operator()(const CScriptID& id) const { return addr->Set(id); }
+    bool operator()(const CNoDestination& no) const { return false; }
+};
+
+} // anon namespace
+
 bool CBitcoinAddress::Set(const CKeyID& id)
 {
     SetData(Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS), &id, 20);
diff --git a/src/main.cpp b/src/main.cpp
index 3586dba4d..b8d8134da 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3404,7 +3404,7 @@ bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, const
                         REJECT_OBSOLETE, "bad-version");
 
     // Check proof of work matches claimed amount
-    if (fCheckPOW && !CheckProofOfWork(block.GetPoWHash(), block.nBits, consensusParams))
+    if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams))
         return state.DoS(50, error("CheckBlockHeader(): proof of work failed"),
                         REJECT_INVALID, "high-hash");
     return true;
diff --git a/src/miner.cpp b/src/miner.cpp
index 20bfd7382..3a117fc70 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -71,8 +71,7 @@ int64_t UpdateTime(CBlock* pblock, const Consensus::Params& consensusParams, con
 
     // Updating time can change work required on testnet:
     if (consensusParams.fPowAllowMinDifficultyBlocks)
-    	pblock->nBits =  GetNextTargetRequired(pindexPrev, pblock, consensusParams, pblock->IsProofOfStake());
-
+        pblock->nBits =  GetNextTargetRequired(pindexPrev, pblock, consensusParams, pblock->IsProofOfStake());
 
     return nNewTime - nOldTime;
 }
@@ -434,7 +433,7 @@ void static BitcoinMiner(const CChainParams& chainparams)
             //
             unsigned int nTransactionsUpdatedLast = mempool.GetTransactionsUpdated();
             CBlockIndex* pindexPrev = chainActive.Tip();
-            int64_t *nFees;
+            int64_t* nFees = 0;
             std::unique_ptr<CBlockTemplate> pblocktemplate(CreateNewBlock(chainparams, coinbaseScript->reserveScript, nFees, false));
             if (!pblocktemplate.get())
             {
diff --git a/src/pow.cpp b/src/pow.cpp
index 297352316..97c9a3592 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -30,20 +30,22 @@ static arith_uint256 GetTargetLimit(int64_t nTime, const Consensus::Params& para
 
 unsigned int GetNextTargetRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params, bool fProofOfStake)
 {
-    unsigned int nTargetLimit = UintToArith256(params.powLimit).GetCompact();
-
-        // Genesis block
-        if (pindexLast == NULL)
-            return nTargetLimit;
+    // Genesis block
+    if (pindexLast == NULL)
+        return UintToArith256(params.powLimit).GetCompact();
 
+    else {
+        unsigned int nTargetLimit = GetTargetLimit(pindexLast->GetBlockTime(), params, fProofOfStake).GetCompact();
         const CBlockIndex* pindexPrev = GetLastBlockIndex(pindexLast, fProofOfStake);
+
         if (pindexPrev->pprev == NULL)
             return nTargetLimit; // first block
         const CBlockIndex* pindexPrevPrev = GetLastBlockIndex(pindexPrev->pprev, fProofOfStake);
         if (pindexPrevPrev->pprev == NULL)
             return nTargetLimit; // second block
 
-    return CalculateNextTargetRequired(pindexPrev, pindexPrevPrev->GetBlockTime(), params, fProofOfStake);
+        return CalculateNextTargetRequired(pindexPrev, pindexPrevPrev->GetBlockTime(), params, fProofOfStake);
+    }
 }
 
 unsigned int CalculateNextTargetRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params, bool fProofOfStake)
@@ -56,8 +58,8 @@ unsigned int CalculateNextTargetRequired(const CBlockIndex* pindexLast, int64_t
             return pindexLast->nBits;
     }
 
-    int64_t nActualSpacing = pindexLast->GetBlockTime() - nFirstBlockTime;
     int64_t nTargetSpacing = params.IsProtocolV2(pindexLast->GetBlockTime()) ? params.nTargetSpacing : params.nTargetSpacingV1;
+    int64_t nActualSpacing = pindexLast->GetBlockTime() - nFirstBlockTime;
 
     // Limit adjustment step
     if (pindexLast->GetBlockTime() > params.nProtocolV1RetargetingFixedTime && nActualSpacing < 0)
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 09560a269..57244f533 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -13,9 +13,9 @@
 
 uint256 CBlockHeader::GetHash() const
 {
-	if (nVersion > 6)
-	        return SerializeHash(*this);
-	    return GetPoWHash();
+    if (nVersion > 6)
+            return SerializeHash(*this);
+        return GetPoWHash();
 }
 
 uint256 CBlockHeader::GetPoWHash() const
@@ -34,8 +34,8 @@ std::string CBlock::ToString() const
         hashPrevBlock.ToString(),
         hashMerkleRoot.ToString(),
         nTime, nBits, nNonce,
-		vtx.size(),
-		HexStr(vchBlockSig.begin(), vchBlockSig.end()));
+        vtx.size(),
+        HexStr(vchBlockSig.begin(), vchBlockSig.end()));
     for (unsigned int i = 0; i < vtx.size(); i++)
     {
         s << "  " << vtx[i].ToString() << "\n";
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 9ed79654a..7e64d1c97 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -960,14 +960,6 @@ void BitcoinGUI::showEvent(QShowEvent *event)
     optionsAction->setEnabled(true);
 }
 
-void BitcoinGUI::showEvent(QShowEvent *event)
-{
-    // enable the debug window when the main window shows up
-    openRPCConsoleAction->setEnabled(true);
-    aboutAction->setEnabled(true);
-    optionsAction->setEnabled(true);
-}
-
 #ifdef ENABLE_WALLET
 void BitcoinGUI::incomingTransaction(const QString& date, int unit, const CAmount& amount, const QString& type, const QString& address, const QString& label)
 {