Qt Designer Custom Widget Not Working

Hello, I'm new in qt4 use before qt3 but not for a long time, so i should consider a newbie.

The problem is that I'm trying to create a custom widget, but when I install it the designer crash, I'm doing this in windows.

The widget is a digital clock, the class for the digital clock works fine, when I create a plugin like the analogclockplugin in the examples, the .dll is created, but when I copy it in the plugins folder and reopen the designer it crashes.

I use qt 4.6 sdk.

thanks,

David