camera error in qt

I want to use camera functionality on my application.

I have built this functionality using the following link:

http://doc.qt.nokia.com/qtmobility-1.2/camera.html#still-images

But when I run on my Nokia N97 device u开发者_C百科sing USB cable it create an error

[Qt Message] Camera error: "Starting viewfinder failed." 
[Qt Message] Camera error: "Starting viewfinder failed." 
[Qt Message] Camera error: "Starting viewfinder failed." 
[Qt Message] Camera error: "Starting viewfinder failed." 
[Qt Message] Camera error: "Starting viewfinder failed." 

I also remembering you that this work in first time but then it create an error

So what is the real problem I install qt.sis,qtmobility.sis,tkr,webtoolkit in my n97 device

The current version is 1.2 (released May 12th) and there where several bug fixes since 1.01. Including one bugfix in 1.1.2 which fixed an error concerning the "Starting viewfinder failed." issue, especially when using QVideoRendererControl. See this bug report for more information.

Maybe you should update your libs and see if the error still exists.