Qt Eclipse Integration and custom widget plugin

What is the correct procedure to compile a custom widget with the Eclipse Integration plugin, under Windows with MinGW?

I tried the following steps, but I cannot see the widget in the Widget Bar.

1. Installed Qt 4.6.1 for Win32 (with MinGW)
2. Installed Eclipse Helios 32-bit (tried with Galileo too)
3. Installed Qt Eclipse Integrator 1.6.1
4. Reconfigured Qt for Integration: configure -release -qtnamespace QtCppIntegration
5. Compiled plugin in release using Eclipse (tried with Creator too)
6. Copied DLL file e "a" file in folder C:\eclipse\plugins\com.trolltech.qtcppdesignerplugins.win32.x86_1.6.1
7. Launched eclipse -clean to reset plugins

Naturally the widget works well under Qt Designer and I can use it there correctly.

Qt Eclipse Integration and Qt Creator binaries for Windows are compiled with Visual C++, so MinGW compiled plugins won't work with them. The standalone Qt Designer is compiled with MinGW, that's why your plugin works with it.

You can recompile Qt Creator with MinGW, I'm not sure about Qt Eclipse Integration.