The wallet at C-Cex will be hung at maintenance until after block 7000.  It's been discussed here for a while, in short you don't want a lot of trading to be occurring when you conceivable could have some major glitches pop up in the system.  Block 7000 is the final alteration of the algo, removing all the X11 crypto and making it stand alone on it's Proof Of Bible Hash (PoBH) crypto.  If there are errors, there are more ways to fix it if trading is effectively frozen (for instance, if a major bug turned up and I got 5M BBP as a block reward, I cannot easily sell it and capitalize off of the glitch).  The exchange will unfreeze when the all clear sounds, which there is no specific time but I'd be very surprised if it's frozen past block 8000 (and that's a very pessimistic value).