SHCameraCapture is the C++ (native) function for launching a dialog ( see http://msdn.microsoft.com/en-us/library/bb160743.aspx)
Its C# (.NET) equivalent is CameraCaptureDialog ( http://msdn.microsoft.com/en-us/library/microsoft.windowsmobile.forms.cameracapturedialog.aspx )
While relatively easy to use, they are both prone to causing memory faults (exceptions indicating low memory) or the API appears to 'lock up'.
While this seems to be an indication that the amount of memory (available RAM) to the application or the system is low, this is likely not the case: it is more than likely an issue concerning STACK memory
Please see the following link for a detailed synopsis of memory related issues on Windows Mobile based devices: http://www.developer.com/tech/article.php/3588021/Big-Mistakes-To-Avoid-in-Windows-Mobile-Development.htm
Here are a few tips to help avoid the issue:
Psion Teklogix has come up with a more attractive alternative to Microsoft's camera dialogs:
This demo shows you how to create a window control (in both C# and C++) that allows you to embed the camera control within a form/window, rather than needing to popup another dialog to handle the camera.