diff --git a/Object.c b/Object.c
index 120d28c141b255292741c1c90a1c1bd8fc5d3950..e9b67fe9ca7246da55d70bfb4c46df357b7f86e0 100644
--- a/Object.c
+++ b/Object.c
@@ -27,7 +27,7 @@ typedef void(*Object_Delete)(Object*);
 
 #define Class(class_)                 ((ObjectClass*)(&(class_ ## _class)))
 
-#define AllocThis(class_) (class_*) xMalloc(sizeof(class_)); Object_setClass(this, Class(class_));
+#define AllocThis(class_) (class_*) xCalloc(sizeof(class_), 1); Object_setClass(this, Class(class_));
  
 typedef struct ObjectClass_ {
    const void* extends;
diff --git a/Object.h b/Object.h
index 19a667c8a6d00322dda59c4a169947c1dc8bb133..c8945e69bc93cfa64d270e0914e648f4aca1f117 100644
--- a/Object.h
+++ b/Object.h
@@ -28,7 +28,7 @@ typedef void(*Object_Delete)(Object*);
 
 #define Class(class_)                 ((ObjectClass*)(&(class_ ## _class)))
 
-#define AllocThis(class_) (class_*) xMalloc(sizeof(class_)); Object_setClass(this, Class(class_));
+#define AllocThis(class_) (class_*) xCalloc(sizeof(class_), 1); Object_setClass(this, Class(class_));
  
 typedef struct ObjectClass_ {
    const void* extends;
diff --git a/darwin/DarwinProcessList.c b/darwin/DarwinProcessList.c
index 5106158317ad751a149c0c360c9c4c4118e3f1c9..fd5f9aef04a059914acedb15c435129c4314770f 100644
--- a/darwin/DarwinProcessList.c
+++ b/darwin/DarwinProcessList.c
@@ -108,7 +108,7 @@ struct kinfo_proc *ProcessList_getKInfoProcs(size_t *count) {
 ProcessList* ProcessList_new(UsersTable* usersTable, Hashtable* pidWhiteList, uid_t userId) {
    DarwinProcessList* this = xCalloc(1, sizeof(DarwinProcessList));
 
-   ProcessList_init(&this->super, Class(Process), usersTable, pidWhiteList, userId);
+   ProcessList_init(&this->super, Class(DarwinProcess), usersTable, pidWhiteList, userId);
 
    /* Initialize the CPU information */
    this->super.cpuCount = ProcessList_allocateCPULoadInfo(&this->prev_load);
diff --git a/linux/LinuxProcess.c b/linux/LinuxProcess.c
index acb30fbc2aa26477d18ce568cf9ed3ddfb8aa4d3..4d941d702e96aa5a11c22bcd867aae04f7e1f388 100644
--- a/linux/LinuxProcess.c
+++ b/linux/LinuxProcess.c
@@ -268,8 +268,7 @@ ObjectClass LinuxProcess_class = {
 };
 
 Process* Process_new(Settings* settings) {
-   LinuxProcess* this = xCalloc(1, sizeof(LinuxProcess));
-   Object_setClass(this, Class(LinuxProcess));
+   LinuxProcess* this = AllocThis(LinuxProcess);
    Process_init(&this->super, settings);
    return (Process*) this;
 }
@@ -441,9 +440,9 @@ long LinuxProcess_compare(const void* v1, const void* v2) {
    case RBYTES: diff = p2->io_read_bytes - p1->io_read_bytes; goto test_diff;
    case WBYTES: diff = p2->io_write_bytes - p1->io_write_bytes; goto test_diff;
    case CNCLWB: diff = p2->io_cancelled_write_bytes - p1->io_cancelled_write_bytes; goto test_diff;
-   case IO_READ_RATE:  diff = p2->io_rate_read_bps - p1->io_rate_read_bps; goto test_diff;
-   case IO_WRITE_RATE: diff = p2->io_rate_write_bps - p1->io_rate_write_bps; goto test_diff;
-   case IO_RATE: diff = (p2->io_rate_read_bps + p2->io_rate_write_bps) - (p1->io_rate_read_bps + p1->io_rate_write_bps); goto test_diff;
+   case IO_READ_RATE:  return p2->io_rate_read_bps > p1->io_rate_read_bps ? 1 : -1;
+   case IO_WRITE_RATE: return p2->io_rate_write_bps > p1->io_rate_write_bps ? 1 : -1;
+   case IO_RATE: return (p2->io_rate_read_bps + p2->io_rate_write_bps) > (p1->io_rate_read_bps + p1->io_rate_write_bps) ? 1 : -1;
    #endif
    #ifdef HAVE_OPENVZ
    case CTID:
diff --git a/linux/LinuxProcessList.c b/linux/LinuxProcessList.c
index 76e56ab44753c2e9ee3b63a46e325d3a7dd2e9e4..2990908bb0badaf660e4f0a5e136f86deb3f49f1 100644
--- a/linux/LinuxProcessList.c
+++ b/linux/LinuxProcessList.c
@@ -6,6 +6,7 @@ in the source distribution for its full text.
 */
 
 #include "LinuxProcessList.h"
+#include "LinuxProcess.h"
 #include "CRT.h"
 #include "StringUtils.h"
 #include <errno.h>
@@ -217,7 +218,7 @@ static void LinuxProcessList_initNetlinkSocket(LinuxProcessList* this) {
 ProcessList* ProcessList_new(UsersTable* usersTable, Hashtable* pidWhiteList, uid_t userId) {
    LinuxProcessList* this = xCalloc(1, sizeof(LinuxProcessList));
    ProcessList* pl = &(this->super);
-   ProcessList_init(pl, Class(Process), usersTable, pidWhiteList, userId);
+   ProcessList_init(pl, Class(LinuxProcess), usersTable, pidWhiteList, userId);
 
    LinuxProcessList_initTtyDrivers(this);