Well, solved the problem, but no real explanation.
I installed 0.5.3 as above. worked (Qt 4.8.4)
then uninstalled and installed 0.6.2. Worked. (Qt 4.8.4)
then uninstalled and installed 0.7.0. Worked. (Qt 5.1.0))
then uninstalled and installed 0.7.2. Worked.
then uninstalled and installed 0.7.4. Worked.
So, 0.7.x (using Qt5) is now working on my PC. No idea of how much of that procedure was necessary.
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