In reply to Andrew Beckett:
For some reason your post was locked (I assume you locked it...) - luckily as moderator I can unlock it, but locking a post means that nobody can reply!
The NC Verilog netlister will report in the CIW any time it can't meet explicit netlisting, and why. Usually it's because of split busses, which may be the case here - sometimes the syntax doesn't really allow passing by name if you have split busses. But the CIW log should tell you the reason - did you look at that?
as you say , I find some warning messages that specify CEll has split buses across module ports and module will printted out with ranges.
Thanks for your help.