Happened to me today too..... must be catchy! This dub guy walked past and I went up to say hello and he completely ignored me, I said Hi again and he just kept looking at some risque birthday cards.
I said: "I didn't know you had gone deaf!" still no reply, just kept looking at the cards. So i just stood nice and close and didn't say anymore, just stood there. The next thing he tried to get away. He had to push past and I stood my ground, but he couldn't even say "excuse me" he just shoved past and fled the store!
How weird!