Could you try this? Go into the Vine Server preferences and make sure it's set up like this. Then try connecting from Remoter.
Let me know how it goes.
(Change Keyboard Layout from the default to "Current Keyboard", and Keyboard Events to "User Session Events")
Thanks,
Raf.
PS: Beta is out, check out your email. To try the new input mode, go into remoter configuration (the edit button at the top toolbar), and change the input mode there. Then try connecting to your mini. Please let me know how this works! (this works with the default settings in vine server, the above suggestion is a work around that shouldn't be required if you set the input mode in remoter, but let me know how both work, please).