@a1ex, The AF jams when you focus a subject then when you try to focus another subject it won't AF anymore. I think it was the Trap Focus that may have affect it after I was using it. Honestly, It's scaring the heck out of me... But when I restarted my DSLR. Things went back to normal. It happened 3 times already
Never noticed that... how to reproduce?
Trap focus is only for manual focus, it has no effect in autofocus modes.
Well, After I turned off Trap Focus and switched my focus mode to AF. Then when I tried to focus a subject it worked. But If I focused to a farther subject, It jams like it the AF won't work anymore. Then I have to restart the cam to make the AF fully work again.
Lens tested: Canon kit lens: 18-55mm f/3.5-5.6
Does it work with plain Canon firmware, without ML?
Yes. But with ML after using Trap Focus, It somehow does that...
Alex. Today, I was shooting with the plain Canon FW, (I reformated my SD card and uninstalled ML in it, but I have another SD card with ML in it) and here's how the problem got worse:
The AF STILL JAMS! Yes. Even with plain Canon FW (But the ML inside the camera is still there). The confirmation light (The green circle light at the lower left corner) and only the AF Point/s light up. When I switched the lens to Manual Focus, The confirmation light lights up when the subject is in focus and also the AF Point/s (I presume this maybe a standard feature that I have not noticed yet until now)
To make the AF work "temporarily" (Due to the fact that the AF Mode lets me down by jamming randomly or upon turning on the cam and trying to auto focus)
[MY THEORY] Due to ML installed in the cam, Trap Focus maybe trying to mess up the AF system.
Alex this is one big bug, man.
I got 2 methods that I am going to try later:
1) I'm gonna try to adjust ML (more specifically, Trap Focus) using my SD Card with ML.
If all else fails...
2) I'm gonna try to remove ML inside the cam and see if AF works full time again.
Good luck to finding the bug fix, Alex. I hope the new ML FW for 600D will fix this big scary bug.