Cancelled Courses Affecting Application?

[bagelslamdunk]

Hi, I will be applying to I/O grad programs for Fall 2016. In terms of research experience, grades, etc. I think I'm fine. However, the major thing that I'm worried about are cancelled courses on my transcript (I have three from last summer and one from last fall). Also, there weren't any extenuating circumstances or anything. How badly will this affect my application..? I'd appreciate any advice or insight, thanks!