The DOF changes because you are changing your camera to subject distance!
Seriously, monti or silkway or whatever you prefer to be called, your comments on here are making me think you're just a troll.
This used to be a helpful and polite forum but lately it's turned into dvxuser, such a shame.
seriously i didnt intend to move from subject
it happened accidently
but even so you can see the difference isnt it?
just its kind of test for intelligence
coz complaining about this is rude
anyway tomorrow i will make another test
maybe problem is that magic lantern doesnt give you exact framing preview in crop mode?
or you know what? im going to make one photo test right now. just give me couple of minutes
updated:
okay test is done
and its going to blow your minds
im going to post it in a second
apdated:
okay here is the test:

Click here for full size review:
http://i036.radikal.ru/1308/87/53761570200d.jpgfor those who still in doubt
here is x10 crop

the 2 crop images are blurry because of camera shake on long focal distance 250-500 mm with no stabilization
OKAY THE DISCUSSION IS OVER
I WAS RIGHT
EVERYONE CORRECT YOUR BELIEFS ABOUT DEPTH OF FIELD IN CROP MODE =)
(This is real test on canon 50d)