Hey,

It seems that you've messed up Qt build but I can't tell what exacly.
I've just build Qt 4.7.4 as static and it works with Qwt without any problem.

I need to recompile it to include gcc (now you need to distribute gcc dll with the binary) and debug libraries.
I'll post how I've done it later, I hope that will help you.

Note Qt 4.6.0 < x > 4.7.0 can't be compiled statically and work with UI widgets according to qt bug database.