Read this story probably sometime back in the ealy-mid 90s about, I believe, a brother and sister who were VR video game designers. All I can really remember about it at this point is that something went wrong with one of their games, some kind of virus, and they split their time between the VR world and the real world trying to track down who was responsible.
New Information: Thinking about it some more, I'm pretty sure I remember getting the book through one of the Scholastic book fair magazines. I'm also starting to feel like 'game' was in the title, but I'm not really sure about that....