I really love digging up old threads like this, but this is the only place I found this problem and I am having it, as well. I just picked up a new 4000D and decided to start from scratch. Using the 3.9CD I created an emergency-boot disk and put in a new 64GB SSD. When I try to run the installer from the emergency disk I get the "Can't get Workbench information" requester.
The only thing I can thing that *might* be an issue is I am using asim-atapi.device to run the CD as that's what's installed in the included system load. I'll try with a different CD driver and see how that works, but if anyone has any experience with this problem I would greatly appreciate some insight.