[MrGaryy]

On Digtial Spy's Tube Talk it says BB9 starts in may

Jerome: "Hey Neil, just wondering when channel 4 will resume showing Ugly Betty because they still have 3 unaired episodes."
Neil: A few more than three. I hear it will be back for a short run alongside the new series of Big Brother at the end of May.

Source, Digital Spy

Also found this:

Big Brother fans - the wait is nearly over. E4 boss Angela Jain tells me they have whittled down the applicants to "50 or 60" and are quizzing those to produce a shortlist of 20 who will then go into hiding The BB house is also in the process of being completely gutted and refitted with a fabulous new look for when the show starts in May. It's scheduled for 13 weeks - oh brother...

Source, The Mirror

And in Star Magazine it says June 6.