Hello,
Firstly, are you using Codewarrior 6.2?
If so it might be the problem where using a demoboard as a BDM adapter for a different off-board device is deliberately crippled. Although I do not think this extends to different size devices of the same family.
I know very little about the Softec device however from reading posts here I gather it is pretty fussy about which devices it works with.
Or perhaps I'm way of base and your doing something wrong in Codewarrior.