Re: whats the difference?
I think you'd write a bit more about your enviroment. Those are all terms, which are not really exactly defined.
For a segmentation error you must work on a system, which works with segmented memory. When you access on a certain segment, which is not loaded or on which you has no rights, than you get a segmentation error.
You get a bus error when, for instance, the bus isn't free for access.
Do you develop PCI-cards or something else?
Gomez