iPhone Wi-Fi transport sequence UI design, has some problem, anyone can help me?

Download code he开发者_如何转开发re: http://www.cocoachina.com/bbs/job.php?action=download&aid=12804

I do it like iPhone BlueTooth transporting, but it has some problem.

For example, there are 2 iphones: A and B

Both Press "Search Devices" button, then start to search devices, after getting others, display the target devices list view.

On A iPhone, press the target device name(here is B iPhone), display a waitting view; And on B iPhone, display a "decide" view with "accept" and "cancel" button.

if B iPhone select "accept", the "decide" view dismiss, start data transport(in my app, it is same as click "cancel" button); and the same time, on A iphone, the waitting view dismissed.

But! On both devices, in target devices list，

If A and B both press target device name at the same time，and on "decide" view of one device, after press "Cancel" button, some times, the "exc_bad_access" error happend.

The error happend at WifiDeviceListController.m line87

Does any one can help me?

Thank you very much～～

The error is here: http://www.cocoachina.com/bbs/attachment/Fid_6/6_7927_2b7ce77107b6c6d.jpg