I’m trying to downgrade from 3.4 to 3.2 due to Plugin compatibility reasons. On Mac Snow Leopard, when I run the 3.2 installer, it seems the 3.2 is not installed in applications, when I use Spotlight to find Unity that link is apparently still to 3.4.x. How do you access the v3.2?
if you don’t rename the unity folder there will only be one unity and thats the last one you install.
if you want to be sure, just delete the unity folder in applications and then install 3.2
but if you downgrade, I would either do it to 3.1 or 3.3, not to 3.2
Why not 3.2 or 3.0?
Yeah I tried deleting the folder but the newly installed Unity is still 3.4.x
Not sure if I have the right dmg’s:
unity-3.1.0.dmg 637.6 MB
unity-3.3.0.dmg 677 MB
Why not 3.0: missing some features and some pretty ugly bugs
Why not 3.2: its the same as 3.3 but missing some relevant bug fixes (there is one new bug though in 3.3 that could enforce 3.2)
Simply put 3.1 and 3.3 are the ‘better incarnations’ of 3.0 and 3.2 
When you remove the unity folder ensure to remove the unity in the bar too given you dragged it there, otherwise the removal fails.
also where do you know from that it is the old version?
I renamed the old unity folder… I assume the new one would install to the default directory, and the Unity icon in the bar on the bottom would link to the new one… Even double clicking the Unity application itself seems only 3.4 would load and not 3.3 or earlier