Replacing Stacks in Memory

[Michael Doub]

I am building a launcher app the loads stacks from DropBox.
I am using

go URL tURL where the tURL is the stack to load using the correct 
DropBox format.

This works great for the first load.  However, if I update the stack in 
DropBox and try to reload tURL, it does not purge the existing stack and 
load the new one.

Is there a way to force a reload?

Regards,
    Mike