I have an app that works great on Leopard but on Tiger I'm getting some errors I can't resolve just from the stack trace.
Is it possible at all to do remote debugging from Leopard to Tiger, and if so, how?
If you are comfortable using gdb directly you can just copy over the symbol files, ssh into the tiger machine and use gdb. Otherwise you should be able to use Xcode's integrated debugger by following the remote debugging instructions described in the documentation.