I'm currently doing an internship at an IT company.
I found they didn't ask me about the amount of time I'm taking for my study. Currently about to start my 4th year in my 5th year of study. They don't seem to mind. They did ask about extra work I might've done during my study, which could be conceived as a subtle way of asking about the additional time for a study that should be finished within 4 years. I however did see this coming and answered with an avoiding response about the part-time jobs I've and projects I've done during the study, and then volunteered some information as to why I'm taking longer than usual.
So I would agree with Michael. They tend not to mind all too much, however having an answer or two ready isn't a bad idea. Bad time in your life, taking time away, all relevant. No-one really studies well when their head is tangled up. Plus you can then use that to explain that you started again at a later point in time, which would shorten the amount of time actually spend on doing the study considerably. If they ask at all that is ;)