Hello, I have the same problem, my inner sis file was not signed. I checked this with SYSContents application found on the internet.
After I found this thread, I did the following:

1) Rebuild...

Thanks, treinio. I solved the problem by copying image to QDir::tempPath().

Ok if it helps: openUrl works with http://url... Also works with mailto:
Just tried without file:/// -- it is even worse. Id doesn't open anything, even a black window.

I can not open image .jpg file with QDesktopServices :: openURL on my device.

I am using:
Qt Creator 2.5.0
Qt 4.7.4 for Symbian Anna (Qt SDK) Release

Device: Nokia C6-01
Qt version: 4.7.4...