No error dialogue on PDF save failure

I was just trying to re-save a changed part as PDF and every time I went back to Explorer, the datestamp on the file hadn't updated, and the content of the PDF was still as it was before I made my changes.

I eventually realised that I had left the PDF open in the Adobe Reader, so therefore MuseScore couldn't write the file, however no error message was displayed.

MuseScore version 1.2, Windows 7.