The SRCSAS18E is a pretty old controller. In fact, our first SAS controller. Because of the age, new operating systems aren't being tested with the SRCSAS18E.
The SRCSAS18E Tested Hardware & Operating Systems List includes validated operating systems for the controller. It includes Microsoft* Windows Server 2003* Small Business Server and was tested for Basic Installation, not stress tested at the time.
In these situations, it's up to the user to test and validate "non-validated" operating systems for their use.