I paid fees on-line on April 19, 2011 , but the date on application form and residence calculation is May 06,2011, do you know if it will be a problem?
I don't think so. I am doing the same thing. As long as you sign the application the day after you qualify and send it on that day or after, you should be fine.
I'm sue the government of Canada will look favorably on you having paid the money a few days earlier ;D