Just like Open Office is a very poor imitation of Microsoft Office full of bugs and incompatabilities unless you're doing very simple stuff.
I admit that I am not a computer techie, but I have been using Open Office for a good couple of years, on all our machines, and have not found it 'buggy' at all. I have created some fairly complex presentations with their 'powerpoint' equiv. and find it as good as, if not better, than .ppt.