Some technical background ...
3 things are needed to startup ML
- Camera with bootflag set
- Bootable card
- ML files on card
If any of this conditions is missing ML won't start.
(For the moment let's forget what's happening if SET is pressed during startup, okay?)
A cam with bootflag will look for a bootable card. If the card is not bootable, ML won't start and cam will operate pretty much like designed by Canon.
If however the card is bootable the camera will try to locate and load AUTOEXEC.BIN.
If Autoexec.bin is missing on a bootable card the cam will get stuck during startup.
And because there is no way for a card to become bootable by itself and because deleting Autoexec.bin and ML dir from a card *without* disabling boot option is *the* most common error which will cause stuck cams I simply don't believe that this card was clean.
And this one
But somehow with the august builds, you need to have ML on your card or the camera won't boot.
is utter nonsense.