Hi Everybody,

We are trying to build Qt-5.3.1 on desktop from Qt source(qt-everywhere-opensource-src-5.3.1.tar.gz).
Our system/PC is of 64bit architecture and OS is Ubuntu-12.04

We are able to build/configured Qt successfully without any error.

But when we are trying to run the application, system is going on "power-save mode" and application
is crashing without any error/warning.

When we are trying to run simple console-based application its running fine. So only GUI based application
is not running.

But with same configuration/building on another system/PC which is having same configuration its running fine.

Why its not working on some of the system and its working on few system, only difference is RAM size, we have
observed that, the PC having 4GB RAM where it is working but where RAM is 2GB its not working.

So, We have tried with lower version of Qt-5.2.1 from source, but we are getting same problem. but with error that is
following"
"QXcbConnection: XCB error: 3 (BadWindow), sequence: 667, resource id: 0, major code: 15 (QueryTree), minor code: 0"

What could be the problem, why its running on some of the system and not running on most of the system.
Is It RAM size problem or what...??

I don't think so its RAM problem, please clarify if anyone aware it.

We build Qt with following configure option:
./configure -qt-xcb

Any suggestions is valuable.

Thanks in advance,
Sanjeet