Actually, the problem is that when you hit enter on IE nowadays, it submits the form and "clicks" the first button in the form for you (i.e. submit's it's value)
So, if you have a large form with lots of text fields, followed by a button that says delete first, and a button that says save second, and you hit return, IE helpfully submits the form and clicks delete for you.
You wouldn't believe how many pages have had to change due to this behaviour of IE.
This is bad behaviour in my opinion, but I don't use that browser or the OSes it runs on, thank the gods.