I've been using OpenOffice for a couple of years and still have serious compatibility issues with MS Word documents in 3.2.1. Tends to happen with tables and text format. Whenever I work on a doc for too long (as in making numerous format changes in various parts of the documents) and then open it in Word, I get random alterations that slaughter the intended presentation, for ex: sections can become bold, change font size, color, type. I really hope it'll be fixed at some point.

Meanwhile, if you have an important document to send in .doc, make sure it looks OK by opening it with wordpad.