I check my WEBCAL (using 30boxes.com and on my iPhone calendar) and i still have the problem.
My task is "xyz" and params are: start "Dec 7" ,due by "Dec 20" and shown on calendar as daily appointment that start at 12:01am (instead of "all day" event)
I have the same problem with my iPhone iCal.
i have several tasks that long few days and until now, it was "all day event" (like birthdays) - one instase in the top of the day. now i have a a task that long all over the days.