Can you check what is the language setting for the text? Is it English:USA? (using character panel)
I would suggest you use find-change in InDesign to get rid of this problem.
We used a converter to convert Quark files into InDesign earlier, but now we created from scratch. The language settings was mixed up some were showing as German and some English: Canada, but we change them to English:UK
Yes, we can use find-change option, but this keeps happening, there must be a solution.