I'm sorry - should have written that the patent was granted in 1997; it was filed in 1994. So I think it gets the longer of 17 years from date of grant or 20 years from application - is that right? Either way it gets to 2014. I don't see it cite any previous US patents, so I'm assuming it wouldn't have any terminal disclaimers.
So I still think the likely expiration date is 2019 assuming they will get the full 5-year extension to which they seem to be entitled.