debugme

Maybe someone could help me with the following question - some peace of assembly code “magically” appears/changes during some kind of initialization. There was a certain peace of assembly code where I wanted to apply a patch, but that code is there only during debugging, once certain initialization has been run. If I look at the same address just after loading the executable, I cannot find that code which I see during debugging (there is a different non-sence code in that address).

Maybe someone would be so nice to explain what is going on there?

Thanks!