we have the same situation... I was granted on March 29, 2007 and came here on April 25, so that was 27 days I phoned homeoffice and I was advice to send my application through post on March 28 which is the earliest day of the 28 days of the qualifying period but it falls on weekend. They said it's alright because they will start counting on the day it was registered on post.
goodluck!
