diff --git a/src/obidmscolumn.c b/src/obidmscolumn.c
index a2eb8ac..a7aa67e 100644
--- a/src/obidmscolumn.c
+++ b/src/obidmscolumn.c
@@ -161,7 +161,14 @@ static char* build_column_file_name(const char* column_name, obiversion_t versio
 
 	// Build the file name
 	version_number_length = (version_number == 0 ? 1 : (int)(log10(version_number)+1));
-	file_name =	(char*) malloc((strlen(column_name) + version_number_length + 6)*sizeof(char));	// TODO check the mallocs...
+	file_name =	(char*) malloc((strlen(column_name) + version_number_length + 6)*sizeof(char));
+	if (file_name == NULL)
+	{
+		obi_set_errno(OBI_MALLOC_ERROR);
+		obidebug(1, "\nError allocating the memory for a column file name");
+		return NULL;
+	}
+
 	if (sprintf(file_name,"%s@%d.odc", column_name, version_number) < 0)
 	{
 		obi_set_errno(OBICOL_MEMORY_ERROR);
@@ -179,6 +186,13 @@ static char* build_version_file_name(const char* column_name)
 
 	// Build the file name
 	file_name =	(char*) malloc((strlen(column_name) + 5)*sizeof(char));
+	if (file_name == NULL)
+	{
+		obi_set_errno(OBI_MALLOC_ERROR);
+		obidebug(1, "\nError allocating the memory for a version file name");
+		return NULL;
+	}
+
 	if (sprintf(file_name,"%s.odv", column_name) < 0)
 	{
 		obi_set_errno(OBICOL_MEMORY_ERROR);
@@ -809,7 +823,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms,
 	if (column_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		//obidebug(1, "\nError opening column file");
+		obidebug(1, "\nError opening column file");
 		free(column_file_name);
 		return NULL;
 	}
@@ -842,7 +856,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms,
 	column->header 			 = mmap(NULL,
 			                  	  	header_size,
 			                  	  	PROT_READ,
-			                  	  	MAP_PRIVATE,
+			                  	  	MAP_SHARED,
 			                  	  	column_file_descriptor,
 			                  	  	0
 			                 	   );
@@ -860,7 +874,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms,
 	column->data   			 = mmap(NULL,
 			                 	 	(column->header)->data_size,
 			                 	 	PROT_READ,
-									MAP_PRIVATE,
+									MAP_SHARED,
 			                 	 	column_file_descriptor,
 			                 	 	header_size
 			                	   );
@@ -1329,12 +1343,12 @@ OBIDMS_column_header_p obi_column_get_header_from_name(OBIDMS_p dms, const char*
 
 	// Fill the header structure
 	header = mmap(NULL,
-			 header_size,
-			 PROT_READ,
-			 MAP_SHARED,
-			 column_file_descriptor,
-			 0
-			 );
+			 	  header_size,
+				  PROT_READ,
+				  MAP_SHARED,
+				  column_file_descriptor,
+				  0
+			 	 );
 
 	if (header == MAP_FAILED)
 	{