There is a bug in HTML Report with the ERD page if you only export 1 sub model the image map for the image is for the master model not the sub model.
There is also a problem with relationship line collisions ( with other lines and with entities), Lines either run over the top of each other or through other entities This might be desirable when in straight line mode as you can add break points to prevent the collisions but with straight line mode turned off you can not move the line components or add new break points.
This can be resolved with careful positioning of the entities but is not ideal. It would be nice if with straight line mode turned off, the lines were aware of other objects and route around entities and if parallel to another line have a minimum spacing between them.
I realise many of these issues are resolved in 3.0 and I have suggested the customer download 3.0 Beta to confirm.