diff --git a/backend/aztec.c b/backend/aztec.c
index b7cfa83b..bb9d1ca5 100644
--- a/backend/aztec.c
+++ b/backend/aztec.c
@@ -102,7 +102,7 @@ int aztec_text_process(unsigned char source[], char binary_string[])
 		}
 		
 		i++;
-	}while(i < maplength);
+	}while(i < (maplength - 1));
 	
 	/* look for blocks of characters which use the same table */
 	blocks = 0;
@@ -136,7 +136,7 @@ int aztec_text_process(unsigned char source[], char binary_string[])
 	if(blockmap[0][blocks - 1] & 8) { blockmap[0][blocks - 1] = 8; }
 	
 	/* look for adjacent blocks which can use the same table (right to left search) */
-	for(i = blocks; i > 0; i--) {
+	for(i = blocks - 1; i > 0; i--) {
 		if(blockmap[0][i] & blockmap[0][i + 1]) {
 			blockmap[0][i] = (blockmap[0][i] & blockmap[0][i + 1]);
 		}
@@ -657,7 +657,7 @@ int aztec(struct zint_symbol *symbol, unsigned char source[])
 			for(i = 0; i <= data_length; i++) {
 				adjusted_string[i] = binary_string[i];
 			}
-		
+			
 			/* Data string can't have all '0's or all '1's in a block */
 			i = 0;
 			do{
@@ -675,7 +675,7 @@ int aztec(struct zint_symbol *symbol, unsigned char source[])
 					insert(adjusted_string, i+(codeword_size - 1), '0');
 				}
 				i += codeword_size;
-			} while (i < strlen(adjusted_string));
+			} while ((i + codeword_size) < strlen(adjusted_string));
 			adjusted_length = strlen(adjusted_string);
 			
 		} while(adjusted_length > data_maxsize);
@@ -725,7 +725,7 @@ int aztec(struct zint_symbol *symbol, unsigned char source[])
 				insert(adjusted_string, i+(codeword_size - 1), '0');
 			}
 			i += codeword_size;
-		} while (i < strlen(adjusted_string));
+		} while ((i + codeword_size) < strlen(adjusted_string));
 		adjusted_length = strlen(adjusted_string);
 		
 		/* Check if the data actually fits into the selected symbol size */
diff --git a/backend/composite.c b/backend/composite.c
index 809140f3..0034c3a6 100644
--- a/backend/composite.c
+++ b/backend/composite.c
@@ -131,10 +131,10 @@ int cc_a(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 	
 	bitlen = ustrlen(source);
 	
-	for(i = bitlen; i < 197; i++) {
+	for(i = bitlen; i < 208; i++) {
 		source[i] = '0';
 	}
-	source[197] = '\0';
+	source[208] = '\0';
 	
 	for(segment = 0; segment < 13; segment++) {
 		strpos = segment * 16;
diff --git a/backend/reedsol.c b/backend/reedsol.c
index a0a84dc5..81515ad4 100644
--- a/backend/reedsol.c
+++ b/backend/reedsol.c
@@ -62,13 +62,6 @@ void rs_init_gf(int poly)
 {
 	int m, b, p, v;
 
-	// Return storage from previous setup
-	if (log) {
-		free(log);
-		free(alog);
-		free(rspoly);
-		rspoly = NULL;
-	}
 	// Find the top bit, and hence the symbol size
 	for (b = 1, m = 0; b <= poly; b <<= 1)
 		m++;
@@ -102,8 +95,6 @@ void rs_init_code(int nsym, int index)
 {
 	int i, k;
 
-	if (rspoly)
-		free(rspoly);
 	rspoly = (int *)malloc(sizeof(int) * (nsym + 1));
 
 	rlen = nsym;
@@ -143,6 +134,12 @@ void rs_encode(int len, unsigned char *data, unsigned char *res)
 		else
 			res[0] = 0;
 	}
+	
+	free(log);
+	free(alog);
+	free(rspoly);
+	rspoly = NULL;
+
 }
 
 void rs_encode_long(int len, unsigned int *data, unsigned int *res)
@@ -166,5 +163,10 @@ void rs_encode_long(int len, unsigned int *data, unsigned int *res)
 		else
 			res[0] = 0;
 	}
+	
+	free(log);
+	free(alog);
+	free(rspoly);
+	rspoly = NULL;
 }
 
diff --git a/backend/rss.c b/backend/rss.c
index c560dd4a..8f03e76d 100644
--- a/backend/rss.c
+++ b/backend/rss.c
@@ -933,7 +933,7 @@ int general_rules(char field[], char type[])
 		current = block[1][i];
 		next = block[1][i + 1];
 		
-		if(current == ISOIEC) {
+		if((current == ISOIEC) && (i != (block_count - 1))) {
 			if((next == ANY_ENC) && (block[0][i + 1] >= 4)) {
 				block[1][i + 1] = NUMERIC;
 			}
@@ -952,7 +952,7 @@ int general_rules(char field[], char type[])
 			block[1][i] = ALPHA;
 		}
 		
-		if(current == ALPHA) {
+		if((current == ALPHA) && (i != (block_count - 1))) {
 			if((next == ANY_ENC) && (block[0][i + 1] >= 6)) {
 				block[1][i + 1] = NUMERIC;
 			}
@@ -1798,8 +1798,12 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 	}
 	
 	/* Now add padding to binary string */
-	if (general_field_type[strlen(general_field) - 1] == NUMERIC) {
-		strcpy(padstring, "000000100001");
+	if(strlen(general_field) != 0) {
+		if (general_field_type[strlen(general_field) - 1] == NUMERIC) {
+			strcpy(padstring, "000000100001");
+		} else {
+			strcpy(padstring, "001000010000");
+		}
 	} else {
 		strcpy(padstring, "001000010000");
 	}