When defining a undirected connection (ending with an '-' without arrow) like aFoo--aBar (no blank before aBar) this does not work for initial letters d, l, r, u at the Bar element, e.g. dFoo--dBar.
The 'd' of 'dBar' is being ignored. The connections is rendered like dFoo--Bar. The result is a wrong name of the element in the diagram.
When explicitely defining class dBar before, the results of the effect become even worse: Now two elements are generated in the diagram, an unconnected 'dBar' and a connected 'Bar'.
The effect has maximum impact, if there are connections to (intended) different classes dBar, lBar, rBar, uBar. These will then all lead to a class named Bar.
I can get around this by inserting a blank between the connection and the Bar element, but nevertheless this seems like a severe bug to me, in particular in more complex diagrams.