Unable to use auto login

After updating my launcher-exe I am no longer able to use auto login.

With a clean .minecraft folder the command line

minecraft.exe <username> <password>

will leave both text fields empty. With

minecraft.exe -u=<username> -p=<password>

Both fields are filled with the correct values but no auto login follows. If I than click on the "login" button I got logged in and I am able to play the game.

I tryed this with both .exe and .jar from minecraft.net

File hashes:
minecraft.exe md5:b63ccb43f2779cbea5d8d3ce2e3d90fb size:263186
minecraft.jar md5:bb99785000fdb3ebadd61a4a347fa042 size:81938

An old minecraft.exe (hd5:0f1931e26c21219db1c90e90037f11f6 size:270142 downloaded ~2011-09-14) works fine.