diff --git a/patsolve/mod3solver.cpp b/patsolve/mod3solver.cpp
--- a/patsolve/mod3solver.cpp
+++ b/patsolve/mod3solver.cpp
@@ -122,6 +122,12 @@
             len = 8;
         for ( int i = len; i >= 0; i-- )
         {
+            if (Wlen[i] == 0) {
+                // there exists no card to move
+                /* TODO: determine if we need to call hashpile here
+                / or do any other work */
+                continue;
+            }
             card_t card = *Wp[24+i];
             Wlen[deck]++;
             Wp[deck]++;
@@ -249,7 +255,12 @@
                     if ( Wlen[i] == Wlen[j] + 1 )
                         continue;
                 }
-                mp->pri = qMin(119, 12 + 20 * Wlen[j] + current_row * 2 + RANK(*Wp[j]) * 5);
+
+                if (Wlen[j]) {
+                    mp->pri = qMin(119, 12 + 20 * Wlen[j] + current_row * 2 + RANK(*Wp[j]) * 5);
+                } else {
+                    mp->pri = 119; // TODO: Find out if this is really correct. We can certainly not touch Wp[j], b ut is this the correct mp->pri value?
+                }
 
                 mp->turn_index = -1;
                 if ( i >= 24 && Wlen[i] == 1 && Wlen[deck] )
diff --git a/patsolve/spidersolver.cpp b/patsolve/spidersolver.cpp
--- a/patsolve/spidersolver.cpp
+++ b/patsolve/spidersolver.cpp
@@ -310,6 +310,7 @@
             bool wasempty = false;
             for (int j = 0; j < 10; ++j)
             {
+
                 if (i == j)
                     continue;
 
@@ -345,7 +346,8 @@
                         printcard( card, stderr );
                         fprintf( stderr, "%d %d %d %d %d\n", i, j, conti[i], conti[j],l );
 #endif
-                        if ( SUIT( card ) != SUIT( *Wp[j] ) )
+                        bool card_stack_j_not_empty = Wlen[j] > 0;
+                        if (card_stack_j_not_empty && SUIT( card ) != SUIT( *Wp[j] ) )
                         {
 			  //fprintf( stderr, "continue %d %d %d %d\n",conti[j]+l, conti[i],conti[j]+l, SUIT( card ) != SUIT( *Wp[j] ) );
                             continue;
@@ -383,8 +385,16 @@
                         else {
                             if ( conti[j]+l+1 != 13 || conti[i]>conti[j]+l )
                             {
-                                card_t card_below = W[i][Wlen[i]-l-2];
-                                if ( SUIT( card_below ) != SUIT( card ) || RANK(card_below) != RANK(card) + 1 )
+                                card_t card_below;
+                                bool exists_card_below = Wlen[i] >= l + 2;
+                                if (exists_card_below) {
+                                    card_below = W[i][Wlen[i]-l-2];
+                                }
+                                if ( !exists_card_below || ( exists_card_below &&
+                                                             (  SUIT( card_below ) != SUIT( card ) ||
+                                                                RANK(card_below) != RANK(card) + 1 )
+                                                            )
+                                    )
                                 {
                                     foundgood = true;
                                 } else {
@@ -426,6 +436,9 @@
 
                     n++;
                     mp++;
+                    if (n >= MAXMOVES) {
+                        goto cannot_store_any_more_moves;
+                    }
                 }
             }
         }
@@ -446,6 +459,8 @@
         break; // one is enough
     }
 
+cannot_store_any_more_moves:
+
     if ( n > toomuch && foundgood)
     {
         mp = Possible;