That is the correct process. However, Securom 7 can be tricky and sometimes works with Securom_Loader (asr), other times with CureRom etc. For Stronghold 2 patch 1.3.1 for example neither program worked with a selfmade image, I could only use it with the original cd in my optical drive. Until on a whim I tried simply disabling my secondary IDE channel (optical drive) and it worked. Try it yourself...
Also, did you try the latest
CureROM ? If you already have CureROM installed, or this latest version also doesn't work, try renaming the CureROM executable to something else, since I've noticed that some copy protections look for a running curerom.exe process...