Script app built in 10.6, how do I get it to run on 10.4.11 and 10.5.x

So I took a script and built it as an application and the info plist in the contents folder says:
Minimum system versions, per-architecture
Intel (64-bit) 10.6

Do I need to recompile the app on the minimum platform to get it work on all, or is there a selection I’m missing when creating the app?

Browser: Safari 531.9
Operating System: Mac OS X (10.6)

Hmmm, even though the plist says the minimum system is 10.6, the resources are all there for the other arches and the app runs on 10.4.11 and 10.5.x.

Browser: Safari 531.9
Operating System: Mac OS X (10.6)