Hi everybody,

Thank you very much for your help!!! Now I can compile the qwt + exemples and designer (and the designer works very well)!
I just modified the qwtconfig.pri line with the correct location of qwt (and I erased the # in front of Exemples, last line).
Then I modified the number 2005 to 2008 in the follow files: qwtconfig.pri, examples.pri, designer.pro
To add the plugin, I copy the plugin\designer elements to the Qt 4.4.1 plugin\designer folder, I copy the qwt\lib to the Qt 4.4.1 lib folder, and finally I copy qwt5.dll in the Qt 4.4.1\bin.
Now all features are working!!!