diff --git a/doomsday/engine/portable/src/cl_world.c b/doomsday/engine/portable/src/cl_world.c
index dad0b94d23..4c27e003c4 100644
--- a/doomsday/engine/portable/src/cl_world.c
+++ b/doomsday/engine/portable/src/cl_world.c
@@ -245,7 +245,7 @@ void Cl_AddMover(uint sectornum, clmovertype_t type, float dest, float speed)
                 dest, speed);
 #endif
 
-    if(speed == 0 || sectornum >= numSectors)
+    if(sectornum >= numSectors)
         return;
 
     // Remove any existing movers for the same plane.
diff --git a/doomsday/plugins/jheretic/src/p_spec.c b/doomsday/plugins/jheretic/src/p_spec.c
index f8749ce21b..6d64eb4764 100644
--- a/doomsday/plugins/jheretic/src/p_spec.c
+++ b/doomsday/plugins/jheretic/src/p_spec.c
@@ -432,6 +432,12 @@ void P_InitPicAnims(void)
 
 boolean P_ActivateLine(linedef_t *ld, mobj_t *mo, int side, int actType)
 {
+    if(IS_CLIENT)
+    {
+        // Clients do not activate lines.
+        return false;
+    }
+
     switch(actType)
     {
     case SPAC_CROSS:
diff --git a/doomsday/plugins/jhexen/src/p_acs.c b/doomsday/plugins/jhexen/src/p_acs.c
index d032010f45..4bbdae1f38 100644
--- a/doomsday/plugins/jhexen/src/p_acs.c
+++ b/doomsday/plugins/jhexen/src/p_acs.c
@@ -359,6 +359,13 @@ boolean P_StartACS(int number, uint map, byte* args, mobj_t* activator,
     acs_t*              script;
     aste_t*             statePtr;
 
+#ifdef _DEBUG
+    if(IS_CLIENT)
+    {
+        Con_Message("P_StartACS: Client is attempting to start a script!\n");
+    }
+#endif
+
     NewScript = NULL;
     if(map && map-1 != gameMap)
     {   // Script is not for the current map.
diff --git a/doomsday/plugins/jhexen/src/p_spec.c b/doomsday/plugins/jhexen/src/p_spec.c
index bce7008bf2..4ddd4727d2 100644
--- a/doomsday/plugins/jhexen/src/p_spec.c
+++ b/doomsday/plugins/jhexen/src/p_spec.c
@@ -614,6 +614,12 @@ boolean P_ActivateLine(linedef_t *line, mobj_t *mo, int side, int activationType
     boolean         buttonSuccess;
     xline_t        *xline = P_ToXLine(line);
 
+    if(IS_CLIENT)
+    {
+        // Clients do not activate lines.
+        return false;
+    }
+
     lineActivation = GET_SPAC(xline->flags);
     if(lineActivation != activationType)
         return false;