As far as calculating the number of hours is concerned, it will not matter. Any work experience in excess of 30 hours per week (or 37.5 hours per week under the old rule) would be truncated down, so it won't add or subtract from the total number of years for your work experience. You won't magically have 2,288 hours for the year you're working 44 hours per week. It would still be 1,560 hours.
However, I think you should still notify them about this mistake. Send an email to Ottawa (I know, they will take forever to reply) at least to clarify, or contact your local MP to get faster response. Better, also have your employer write a letter explaining the mistake if possible. To be honest though, I really don't think it's such a big deal, but better be safe