Unfortunately, I see no problem with the steps you have taken.
The error message you describe is most commonly associated with not having fully uninstalled a previous version of svBuilder-Pro when some files have been left behind and remain on your computer.
It is unlikely that there is a problem with your 'svBuilder-Pro.air' file but you can make sure that it is not corrupt by checking its MD5 hash. It should be 97700925d69d7562465951f4f31ce10d.
I have installed svBuilder-Pro v2.3.1 on my PC successfully (under Abode AIR v3.4) using the same file that you have so the 'svBuilder-Pro.air' package itself should be OK.
Perhaps the Troubleshoot AIR installation | Mac OS web page will help further.
Also, searching through the Adobe AIR Forum may prove to be useful.
I realise that this does not directly solve your problem but I hope it points you in the right direction.
If I think of anything else which may help, I will be sure to post back to let you know.
Please note that if trying to re-install svBuilder-Pro (even after having failed to do so), make sure that there is no 'svBuilder-Pro' entry in your Applications folder. If there is, delete it and then empty your Trash before attempting to install svBuilder-Pro again.
SimpleViewer Support Team