Make install prevents Qt 3.3.3 from running

Attempting to install Qwt 5.1.0 on a RedHawk operating system (Redhat Linux Enterprise 4.1). Performed the following steps:

1. Copy qwt-5.1.0.tar.bz2 file to /root/Qwt/
2. Extracted files into /root/Qwt/qwt-5.1.0/
3. cd /root/Qwt/qwt-5.1.0/qwt-5.1.0/
4. Modified qwtconfig.pri to allow examples to be automatically built (uncommented last line in file).
5. qmake
6. make
7. make install

At this point, Qt (3.3.3) cannot be invoked (previously to the make install Qt came up correctly). Running Qt from the command line /usr/lib/qt-3.3/bin/designer results in a segmentation fault.

Added to /etc/ld.so.conf.d the following line:
/usr/local/qwt-5.1.0/lib

The system was rebooted and Qt was still unaccessible.

Performed a make uninstall. It was observed that Qt was now accessible.

Any suggestions?

Do you mean the designer by what you call Qt ?

Uwe

Yes, /usr/bin/designer