Vincent,
SME and Promise => forget it.
SME does not use the same kernel as the general download versions of Redhat Linux, which are the only versions that Promise releases drivers for.
ESSG 4.1.2 was the last version I remember that uses a kernel that matches a standard RedHat Distribution, which is why you managed to get it to work.
Just search the forums for Promise and you will see all the attempts (and failures) others have had before you.
The problem is not only with Promise cards either. Other controllers suffer the same fate. All the talk about these cards being software only and what not serves no real purpose and misses the point about these card altogether, which is the sheer ease of replacing and rebuilding a mirror after a drive failure.
Kelvin