I have had my bandit Dos for nearly a month. I have used it max 7 times and I am SUPER careful with it. It has never smashed done on the water or sand. When used it last two times, it has lost quater of the pressure in less than 2 hours. I cannot find any problems with the inflate or deflate valves.
Has anybody else had any problems with the new Dos ????
I've been riding my 10m Dos since Dec and had some long sessions (4 hours +), but never experienced a slow loss of pressure. And I have smacked both beach and water hard with it more than a few times. Always holds up fine though. Built tough!
The only time mine has deflated was after the deflate valve released after a particularly hard hit on the water. After this happened I noticed that the little tab on the valve can interfere with the velcroes ability to secure the valve in place. I now ensure that I spit on the valve before closing it to inflate, and turn the tab to the side and make sure that the velcroe is really tight. Havnt had the same problem again.
Hope this helps!
Case
I been using a 9 for two months now and no issues, is it LE or struts, you have to take the bladder out and check for location of leaks and repair or replace 
, maybe bad luck, maybe shop will do it for you with a new bladder?
Sounds like a standard type of leak to me. This can happen on any kite. Your kite bladder is very thin and any small sharp object can put a hole in it no matter how careful you are.
Pump it up, grab a bucket of soapy water and a sponge and wipe it over till you see bubbles. Start with the obvious spots like the tips and valves. It might take a while as you have described a very slow leak.
Once found just stick a patch on.
Hi Steve
Talks for the advise, dad and I tried it in the shed this morning and found the leak. That didn't stop me, we went for a 2 hour session this arvo and it flew perfectly :D. Now we just have to pull the bladder out and stick a patch on it.
Thanks Again Steve 
The kites less than a month old!!, Take it back to the shop you purchased from and ask for them to check it. It maybe a faulty bladder, if so, they may replace.
