Bitmask EIP reports "not supported" when started

From current develop branch, as of today:

1. Start bitmask, connect eip.
2. Quit while EIP is on
3. Start bitmask again... reports an EIP error "Not Supported"
4. Button "Turn ON" is enabled, but won't do anything.
5. If I then login, EIP starts and works (but only if I have not already pressed Turn ON).

Problem does not appear if quitting while EIP is off, regardless of login state.

(from redmine: created on 2014-05-28, closed on 2014-06-02, duplicates #5721 (closed))