Extraction suppression problem

First time posting on Tessitura Network. Looking forward to getting (and perhaps one day giving) answers.

I'm creating an extraction for a mailing. The top-prioritized field is a suppression drawn from a list, which includes anybody giving after a certain date range.

Yet when I save the full extraction to a list, several of the constituents who appeared in the list I suppressed remain.

The constituents in question meet other criterea in the extraction (because they gave within the date range I'm looking for), but because they also gave after the aforementioned date range, I suppressed them.

Any idea why they're still showing up?