diff --git a/cpu-miner.c b/cpu-miner.c
index 85d4d2b..2b04c5c 100644
--- a/cpu-miner.c
+++ b/cpu-miner.c
@@ -460,11 +460,14 @@ static bool submit_upstream_work(CURL *curl, struct work *work)
 	bool rc = false;
 
 	/* pass if the previous hash is not the current previous hash */
+	pthread_mutex_lock(&g_work_lock);
 	if (memcmp(work->data + 1, g_work.data + 1, 32)) {
+		pthread_mutex_unlock(&g_work_lock);
 		if (opt_debug)
 			applog(LOG_DEBUG, "DEBUG: stale work detected, discarding");
 		return true;
 	}
+	pthread_mutex_unlock(&g_work_lock);
 
 	if (have_stratum) {
 		uint32_t sent;
@@ -894,6 +897,7 @@ static void *miner_thread(void *userdata)
 		struct timeval tv_start, tv_end, diff;
 		int64_t max64;
 		uint64_t umax64;
+		bool extrajob = false;
 		int rc;
 
 		// &work.data[19]
@@ -901,13 +905,24 @@ static void *miner_thread(void *userdata)
 		uint32_t *nonceptr = (uint32_t*) (((char*)work.data) + wcmplen);
 
 		if (have_stratum) {
-			while (time(NULL) >= (g_work_time + opt_scantime) && !work_done)
-				usleep(500*1000);
-			work_done = false;
-			pthread_mutex_lock(&g_work_lock);
+			uint32_t sleeptime = 0;
+			while (!work_done && time(NULL) >= (g_work_time + opt_scantime)) {
+				sleeptime++;
+				usleep(50*1000);
+				if (sleeptime > 5) {
+					extrajob = true;
+					break;
+				}
+			}
+			if (sleeptime)
+				applog(LOG_DEBUG, "sleeptime: %u ms", sleeptime*100);
 			nonceptr = (uint32_t*) (((char*)work.data) + wcmplen);
-			if ((*nonceptr) >= end_nonce)
+			pthread_mutex_lock(&g_work_lock);
+			extrajob |= work_done;
+			if ((*nonceptr) >= end_nonce || extrajob) {
+				work_done = false;
 				stratum_gen_work(&stratum, &g_work);
+			}
 		} else {
 			int min_scantime = have_longpoll ? LP_SCANTIME : opt_scantime;
 			/* obtain new work from internal workio thread */
@@ -946,11 +961,11 @@ static void *miner_thread(void *userdata)
 			(*nonceptr) = (0xffffffffUL / opt_n_threads) * thr_id; // 0 if single thr
 		} else
 			(*nonceptr)++; //??
-		pthread_mutex_unlock(&g_work_lock);
 		work_restart[thr_id].restart = 0;
 
 		if (opt_debug)
 			applog(LOG_WARNING, "job %s %08x", g_work.job_id, (*nonceptr));
+		pthread_mutex_unlock(&g_work_lock);
 
 		/* adjust max_nonce to meet target scan time */
 		if (have_stratum)
@@ -962,15 +977,18 @@ static void *miner_thread(void *userdata)
 		max64 *= (int64_t)thr_hashrates[thr_id];
 
 		if (max64 <= 0) {
+			/* should not be set too high,
+			   else you can miss multiple nounces */
 			switch (opt_algo) {
 			case ALGO_JACKPOT:
 				max64 = 0x1fffLL;
 				break;
 			case ALGO_BLAKECOIN:
 				max64 = 0x3ffffffLL;
+				break;
 			case ALGO_BLAKE:
 				/* based on the 750Ti hashrate (100kH) */
-				max64 = 0x3ffffffLL;
+				max64 = 0x1ffffffLL;
 				break;
 			default:
 				max64 = 0xfffffLL;
@@ -1008,7 +1026,7 @@ static void *miner_thread(void *userdata)
 					work_restart[thr_id].restart = 1;
 					hashlog_purge_old();
 					// wait a bit for a new job...
-					sleep(1);
+					usleep(500*1000);
 					(*nonceptr) = end_nonce + 1;
 					work_done = true;
 					continue;
diff --git a/util.c b/util.c
index 04209e0..6ed44c0 100644
--- a/util.c
+++ b/util.c
@@ -1020,7 +1020,7 @@ static bool stratum_notify(struct stratum_ctx *sctx, json_t *params)
 	int merkle_count, i;
 	json_t *merkle_arr;
 	unsigned char **merkle;
-	int ntime;
+	int ntime, hoffset;
 
 	job_id = json_string_value(json_array_get(params, 0));
 	prevhash = json_string_value(json_array_get(params, 1));
@@ -1078,7 +1078,8 @@ static bool stratum_notify(struct stratum_ctx *sctx, json_t *params)
 	hex2bin(sctx->job.coinbase, coinb1, coinb1_size);
 	memcpy(sctx->job.coinbase + coinb1_size, sctx->xnonce1, sctx->xnonce1_size);
 
-	sctx->bloc_height = le16dec((uint8_t*) sctx->job.coinbase + 43);
+	hoffset = coinb1_size - 15; // 43;
+	sctx->bloc_height = le16dec((uint8_t*) sctx->job.coinbase + hoffset);
 	if (!sctx->job.job_id || strcmp(sctx->job.job_id, job_id))
 		memset(sctx->job.xnonce2, 0, sctx->xnonce2_size);
 	hex2bin(sctx->job.xnonce2 + sctx->xnonce2_size, coinb2, coinb2_size);
@@ -1125,7 +1126,7 @@ static bool stratum_set_difficulty(struct stratum_ctx *sctx, json_t *params)
 	sctx->next_diff = diff;
 	pthread_mutex_unlock(&sctx->work_lock);
 
-	applog(LOG_INFO, "Stratum difficulty set to %g", diff);
+	applog(LOG_WARNING, "Stratum difficulty set to %g", diff);
 
 	return true;
 }