Testing With Selenium IDE


I would like to create ui-tests for a Vaadin App with Selenium over the Selenium IDE.
My Problem is that interactions with comboboxes and checkboxes are not possible when using Selenium.
Since Vaadin Testbench is based on Selenium I thought that there has to be a way to interact with those components.
Is that the case? And if so, could anybody tell me how to do it?