Five minutes ago I was typing an e-mail, and looked twice at the last sentence I'd written.
"If I wasn't using this particular browser email (that doesn't let me get fancy)..."
My mental grammar-checker started making a clunking noise over it, because I am using that browser email, and anything else is contrary to fact.
I looked it up just to be sure, and found this entertaining blog post about wasn't and weren't.
So I wasn't wrong. (About being wrong.)