The printing seems to be totally broken on Mac OS X when printing to native printer. Here is a simple example:
This shows print dialog, but nothing prints when dialog is accepted. Instead it gives the following message to application output dialog:
There is no problem when using Qt 4.8.4 on Mac.
This works on Windows with Qt 5.1. It works also on Mac OS X with Qt 5.1 when printing to pdf file (setOutputFormat is PdfFormat).