Export to MP3 Defaults to flac

Okay, this is exactly what I'm doing:
    I am using the Editor in Pyro Audio Creator.
    I have hundreds of audio ideas recorded & I'm exporting them all as mp3s.

    1. I open a project, edit & normalize if needed,  
    2. Then I go to File > Save As > Mp3  & the Save As window opens.
    3. Here is the problem - in the Save As window the File Name & File Type both default to *.flac.
        Since I want Mp3 I have to:
    4. type the new file name with the .mp3 extension then select Mp3 in the File Type list.
            If I select Mp3 in the File Type list & don't type the .mp3 extension the file won't save as an mp3.
    5. Then I click Save & the MP3 Save options window opens & everything for there is fine.

My question is:
    How do I make the Save As window default to Mp3 & not flac?