Looking at all the variables involved in creating and displaying a web page (operating system and version thereof) browser (and versions thereof), WordPress (and versions thereof) and the theme, it is obvious that the combinations is virtually infinite.
I can't speak about anything other than what I run (Firefox (v 17.0), Google Chrome (v 24), MSIE (v 9.0), WP (v3.5.1) and ai1ec (v 1.9.2 Pro), I can say that FOR ME, ai1ec works as advertised.
However, I did had an issue wherein the display mode and categories buttons did not work. I called my theme provider and they wrote two code segments that, after I placed them in my theme style.css file, caused the calendar to work perfectly.
The point of this is that, at least in my situation, ai1ec works perfectly. This leads me to believe that conflicts are probably caused by the underlying code of you theme and the ai1ec plugin. Who you choose to blame is up to you.