start_activity opens modified app

Opening activity on android emulator (4.4) modifies app in some way and make it crash on login request.
Was debugged with ruby console.
So if app started by hand (typing on app in emulators application list) login passes and everything works ok.
But when it starts with new driver instance, or via console with start_activity method login request crash application.
crash related to android accounting class
E/AndroidRuntime( 3044): java.lang.IllegalArgumentException: the type must not be empty: null
E/AndroidRuntime( 3044): at android.accounts.Account.(Account.java:51)

here is stacktrace: http://pastebin.com/pqsqc9V5

Any suggestions would be appreciated