I've recovered, if not all, at least most of my ICQ database. But I had to go for an installation of ICQ 2000b, anyway.
The question is that from version to version, the ICQ databases have changed their format to account for greater functionality.
But not only I could recover it (almost all, if not all, really), I was also able to include all th eUINs I've registered throughout time, for different places, and transfer the ICQ database from my laptop to this one.
So I can say I'm quite happy!