Folks, I'm sure someone here knows how to help me with this issue. I get that I'm a mac dummy, but I'm here in the land of mac experts - I know somebody can help me with this. This should be an easy one for you mac pro's!
I'm totally not a pro, and may not have the right answer for you, but I know what it feels like to shout into the void.
Have you tried right-clicking (control-clicking) (two-finger-clicking) on the music or movie file, and selecting "get info" from the drop down menu? If you do that, an information pane opens, with lots of metadata and information about the file and some adjustable options (some of these may be tucked away under disclosure triangles which need to be ticked open).
One of them says "open with" and has a small window showing the current application designated to open this particular file. If you don't like the app that is selected, you can change it. If you do like it, you can keep it. And the part which would probably help you is the button underneath, which says "change all." So, if you like opening your movie file with VLC, you can click 'change all' and then any file that ends with .mkv or whatever you're choosing, will default to opening with VLC. The same thing applies to getting apps you don't want launching (by their exclusion).
There may be something in iPull's preferences that has it defaulting to open mp3 with Quicktime. But if you tell your mac to always open mp3s with itunes, that should override iPulls settings. If not, it should be easy enough to go to iPulls preferences and turn off whatever the setting is for always open such and such with blah blah blah.
I hope this helps. I'm about to ask for help here myself. Never thought I'd be answering a query.
Red