Apps Odd stuff happening in Eclipse

[Cymro]

I am following the beginners tutorials on using Eclipse to write apps
This one Hello, World | Android Developers
I copy and paste the first missing line into my program in Eclipse as it asks and hit enter and eclipse scrolls up the code and deletes my new code.

This is baffling. How do I solve it?

 

[jiminaus]

Do means when you replace:

setContentView(R.layout.main);

with:

TextView tv = new TextView(this);
tv.setText("Hello, Android");
setContentView(tv);

What exactly are you doing? I don't get why you hitting Enter, for example. It should be enough to copy the new code, highlight the old code, then hit Control+V (or Command+V on Mac) to paste the new code over the old code.

Also, which operating system and which version of Eclipse are you using?