diff --git a/iguana/iguana777.c b/iguana/iguana777.c
index b45290593..d840fec73 100755
--- a/iguana/iguana777.c
+++ b/iguana/iguana777.c
@@ -471,6 +471,12 @@ void iguana_helper(void *arg)
                     if ( coin->polltimeout < polltimeout )
                         polltimeout = coin->polltimeout;
                     //printf("call spendvectors.%d\n",bp->hdrsi);
+                    if ( coin->PREFETCHLAG > 0 )
+                    {
+                        iguana_ramchain_prefetch(coin,&bp->ramchain,0);
+                        if ( bp->hdrsi > 0 )
+                            iguana_prefetch(coin,bp,bp->hdrsi-1,1);
+                    }
                     if ( (retval= iguana_spendvectors(coin,bp,&bp->ramchain,0,bp->n,0)) >= 0 )
                     {
                         flag++;
diff --git a/iguana/iguana777.h b/iguana/iguana777.h
index 4a1f2228b..d5e48a703 100755
--- a/iguana/iguana777.h
+++ b/iguana/iguana777.h
@@ -851,6 +851,7 @@ int32_t iguana_bundleissuemissing(struct iguana_info *coin,struct iguana_bundle
 int32_t iguana_blocksmissing(struct iguana_info *coin,int32_t *nonzp,uint8_t missings[IGUANA_MAXBUNDLESIZE/8+1],bits256 hashes[],double mult,struct iguana_bundle *bp,int32_t capacity);
 FILE *myfopen(char *fname,char *mode);
 int32_t myfclose(FILE *fp);
+void iguana_prefetch(struct iguana_info *coin,struct iguana_bundle *bp,int32_t width,int32_t flags);
 
 extern int32_t HDRnet,netBLOCKS;
 
diff --git a/iguana/iguana_blocks.c b/iguana/iguana_blocks.c
index 2c0a6820e..95673a200 100755
--- a/iguana/iguana_blocks.c
+++ b/iguana/iguana_blocks.c
@@ -328,7 +328,7 @@ struct iguana_block *_iguana_chainlink(struct iguana_info *coin,struct iguana_bl
         else
         {
             char str[65];
-            if ( bits256_nonz(block->RO.prev_block) != 0 )
+            if ( 0 && bits256_nonz(block->RO.prev_block) != 0 )
                 printf("chainlink error: cant find prev.(%s)\n",bits256_str(str,block->RO.prev_block));
             iguana_blockunmark(coin,block,0,-1,0);
             //memset(&block->RO.prev_block.bytes,0,sizeof(block->RO.prev_block));
diff --git a/iguana/iguana_unspents.c b/iguana/iguana_unspents.c
index c69f532ac..b3b36f528 100755
--- a/iguana/iguana_unspents.c
+++ b/iguana/iguana_unspents.c
@@ -817,12 +817,6 @@ int32_t iguana_spendvectors(struct iguana_info *coin,struct iguana_bundle *bp,st
     if ( strcmp(coin->symbol,"BTC") == 0 )
         printf("start UTXOGEN.%d max.%d ptr.%p millis.%.3f\n",bp->bundleheight,n,ptr,startmillis);
     //txidind = spendind = rdata->firsti;
-    if ( coin->PREFETCHLAG > 0 )
-    {
-        iguana_ramchain_prefetch(coin,ramchain,0);
-        if ( bp->hdrsi > 0 )
-            iguana_prefetch(coin,bp,bp->hdrsi-1,1);
-    }
     starttime = (uint32_t)time(NULL);
     txidind = B[starti].firsttxidind;
     spendind = B[starti].firstvin;
@@ -862,7 +856,7 @@ int32_t iguana_spendvectors(struct iguana_info *coin,struct iguana_bundle *bp,st
                         }
                         if ( coin->PREFETCHLAG > 0 && now >= spentbp->lastprefetch+coin->PREFETCHLAG )
                         {
-                            //printf("prefetch[%d] from.[%d] lag.%d\n",spentbp->hdrsi,bp->hdrsi,now - spentbp->lastprefetch);
+                            printf("prefetch[%d] from.[%d] lag.%d\n",spentbp->hdrsi,bp->hdrsi,now - spentbp->lastprefetch);
                             iguana_ramchain_prefetch(coin,&spentbp->ramchain,2);
                             spentbp->lastprefetch = now;
                         }
@@ -1611,7 +1605,7 @@ int32_t iguana_spendvectorconvs(struct iguana_info *coin,struct iguana_bundle *s
     spent_hdrsi = spentbp->hdrsi;
     ramchain = (spentbp == coin->current) ? &coin->RTramchain : &spentbp->ramchain;
     numpkinds = ramchain->H.data->numpkinds;
-    iguana_ramchain_prefetch(coin,&spentbp->ramchain,0);
+    iguana_ramchain_prefetch(coin,ramchain,0);
     spentU = (void *)(long)((long)ramchain->H.data + ramchain->H.data->Uoffset);
     for (i=converted=0; i<n; i++)
     {