[Qt-interest] unable to run application in background

[linux newbie]

Hi,

I tested some of the example application in our ARM based embedded
platform and it is working, but when I tried to run it in the
"background"(by adding '&' at the end of command), system freezes.

When I gave the following command
./Qt_test -qws &
system freezes.

Our console is running at ttyS0(serial port) and when I gave 'ps'
command, it shows the
891 root     18536  T    ./Qt_test -qws

It seems that Qt process is terminated and I couldnt kill that process
using kill command.

Can anyone share their thoughts in this regard?

Thanks