Fields in Sametime account dialog "jump around" and get emptied at random

Dear maintainers,

this is probably an upstream bug, as I have seen it on openSuse 42.x as well.

If you add an account for IBM Sametime in pidgin, it is hard to enter any information at all.
If you open the dialog, fields get emptied at random, or dialog boxes move inside the dialog.

For example, if I change my password in the 3rd-party application Lotus Notes and reconnect via pidgin, it asks me (correctly) to modify the account to reflect these changes.
As soon as I click on "modify account" I see an empty "server" field.

On openSuse 42.x and later, it is possible to resize the dialog. Upon resizing, the fields will jump around, which means lables are not next to their checkboxes anymore.