more info here:
http://en.wikipedia.org/wiki/Campro_engine

For those lazy ppl, i'll try to summarize. There are 3 Campro engines out there:
1. Plain old CamPro (all proton cars after Waja and before New Saga)
2. CamPro IAFM (New Saga and latest batch Persona)
3. CamPro CPS (Gen-2 CPS and Waja CPS)

The plain CamPro was supposed to have cam profile switching technology since the very first version, but it was dropped to save cost(?). As a result it had a big ugly torque dip at lower rpms (i.e. no power unless you rev high).

IAFM stands for Intake Air Fuel Module (lol @ i am fat man). I dont know how it works, but basically the torque dip is gone. No need to rev so high, easier to handle in city driving and traffic jams.

CPS is the real Cam Profile Switching technology, which also has the same effect as IAFM. Maybe a little bit more overall power. It comes together with something called VIM (Variable Intake Manifold) but usually it's shortened to CPS only.

Interesingly, if you try to read CamPro CPS in full (no short form) then it sounds like Cam Profile Cam Profile Switching.  It should also be noted that none of these are cutting edge technology developed by proton. They exist in many other cars, probably under different names.

Sorry if i made any mistake in my post...cya