The issue as described below is solved. Logos will be displayed in 200*50 px again.
We are currently working on a bug which makes the logo on the top left corner of your screen being displayed too big (it gets the size of the original image size). After we've solved this, the logo will be displayed in the correct size.
What can you do in the meantime?
In order to display the logo in the correct size, please resize your logo to this standards:
Size: 50px 200px