Oh ok, thanks, that is a grammatical construct we haven't yet encountered here. What do you call that?
I think that this is equivalent of subjunctive in Romance Languages:
Some people sometimes deliberately use wrong pronunciation in order to sound humorous (or for any other stylistic effect). Others pick that up and start talking the same way, without realizing why they do so. "Chcem" is one of those words that became quite common, even though it's wrong.