strange symbols randomly inserted into recent pages?? Please help!

Hello!
I just made a bunch of new pages today.
They were working fine earlier.

THEN, I upgraded by WordPress to 2.7
I also upgraded my nextGen gallery.

And then I revisited my pages and this is the kind of thing I observed:

“He goes on to say that an objecta€?s being and an objecta€?s unity are really the same thing, this especially seen in the fact that when being is generated and destroyed, unity is as well, and that a€?a man existsa€? is the same as saying a€?one man exista€? (1003b 27). From this Aristotle goes on to say that an objecta€?s unity comes from its substance, and thus the investigation of being is really the investigation of substances.”

For more examples
https://little-hypotenuse.com/heidegger-being
https://little-hypotenuse.com/ethical

In all TEN of the new pages. When I go to edit the pages those symbols have been inserted, I think in substitution of quotation marks, apostrophes, etc.

Why is this happening and how can I make it go away??

Thank you!