Thanks again for the replies!
Unfortunately it's an older macbook I'm using as well, so I can't upgrade the OS.
At the download it clearly states though that the requirements for Fritzing are OSX 10.7 and up.
Mac - OSX 10.7 and up, though 10.6 might work too
If the OS version is the culprit here, it might be an idea to change the requirements stated?
Still hoping there is a workaround for this though 
Michiel