diff --git a/web/yaamp/core/backend/payment.php b/web/yaamp/core/backend/payment.php
index 7a5eaa5..b3704ea 100644
--- a/web/yaamp/core/backend/payment.php
+++ b/web/yaamp/core/backend/payment.php
@@ -171,17 +171,19 @@ function BackendCoinPayments($coin)
 		if(!$user) continue;
 		if(!isset($addresses[$user->username])) continue;
 
+		$payment_amount = bitcoinvaluetoa($addresses[$user->username]);
+
 		$payout = new db_payouts;
 		$payout->account_id = $user->id;
 		$payout->time = time();
-		$payout->amount = bitcoinvaluetoa($user->balance*$coef);
+		$payout->amount = $payment_amount;
 		$payout->fee = 0;
 		$payout->idcoin = $coin->id;
 
 		if ($payout->save()) {
 			$payouts[$payout->id] = $user->id;
 
-			$user->balance = bitcoinvaluetoa(floatval($user->balance) - (floatval($user->balance)*$coef));
+			$user->balance = bitcoinvaluetoa(floatval($user->balance) - $payment_amount);
 			$user->save();
 		}
 	}
diff --git a/web/yaamp/modules/thread/CronjobController.php b/web/yaamp/modules/thread/CronjobController.php
index 4af3982..fc8a2a3 100644
--- a/web/yaamp/modules/thread/CronjobController.php
+++ b/web/yaamp/modules/thread/CronjobController.php
@@ -57,8 +57,10 @@ class CronjobController extends CommonController
 			dborun("update jobs set active=false");
 
 		BackendBlockFind1();
-		BackendClearEarnings();
-		BackendRentingUpdate();
+		if(!memcache_get($this->memcache->memcache, 'balances_locked')) {
+			BackendClearEarnings();
+			BackendRentingUpdate();
+		}
 		BackendProcessList();
 		BackendBlocksUpdate();
 
@@ -209,10 +211,13 @@ class CronjobController extends CommonController
 
 		sleep(10);
 		BackendDoBackup();
-
 		memcache_set($this->memcache->memcache, 'apache_locked', false);
 
+		// prevent user balances changes during payments (blocks thread)
+		memcache_set($this->memcache->memcache, 'balances_locked', true);
 		BackendPayments();
+		memcache_set($this->memcache->memcache, 'balances_locked', false);
+
 		BackendCleanDatabase();
 
 	//	BackendOptimizeTables();