When I was in the Crimea I heard someone saying a number and at first I didn't understand what he was saying.

He pronounced "шестьдесят" as "шессят".

Of course I thought he said "шестьсот", but six hundred was impossible in this situation. This isn't just a pronunciation difference, it's a completely different word! I thought this guy was just strange, but I heard it again, and again, and again.

Does this have something to do with the Ukrainian language? What's the story with this? Have any of you ever heard something like that?