What's the deal with import files in D2?

[Heinz]

I come from D1 DMD1.030 programming era and i use import files 
(.di files) a lot as companion for my custom static libs (.lib). 
But now in D2 (and apparently in later D1 versions) they seem to 
be causing a lot of trouble, i mean, what's their purpose if i 
still have to compile them to get rid of undefined symbols mainly 
Module_Init, Module_Info and Module_Ctor.
Or is this a problem with the -lib switch that forgets to include 
those symbols in static libs? I mention this because i'm also 
getting symbol errors for my class(es) Ctors as well. It seems 
that some symbols are not being included in static libs. 
(happends in the newly released DMD2.064.2 as well).

I hope you have experienced the same to understand what i mean.