set_es uses es_handle, not ent id.
PHP Code:
// These functions are used with the entity_state data structure (FM_AddToFullPack)
// Get: 0 extra params - Return integer; 1 extra param - by ref float or vector or array
// Set: Use anything
// Use 0 for es_handle to specify the global entity_state handle
native get_es(es_handle, EntityState:member, {Float,_}:...);
native set_es(es_handle, EntityState:member, {Float,_}:...);
Also, when I used AddToFullPack, I had to take out returns for it to work (might be just my code)...