What happens if while off-line, you open MIST switch it to the test network, close it, go online, open MIST and fire the transaction?

I have a similar problem with an account I created that is stuck doing nothing, I delved into all the files via deep text search looking to delete that specific one. I have not followed through though, when I do and if it works, I will report back.

edit add:

While I wait for my MIST to sync: