I don't know exactly how the signal / slot system works but I have an idea why you can't use quint32: In the connect you have to specify the type as a name, which is converted to a const char* by a macro. But how should the compiler guess that "unsigned int" is equal to "quint32"?

Another problem is that the quint8 seems to work OR that the parameters are queued from right to left. Then connect could stop after the quint32.

My suggestion is that you try to use unsigned int or do you really need exactly 32 bit, with more being an error?