Please advise how I can correct this error:

In InDesign CS, having chosen the same color for both text and box
borders, the text prints out in a different colour (typically darker).

This problem was not evident in InDesign 2.02 and first became
apparent on 'converted' (ie 2.02 files opened in CS) doents.

Reading through the NG, no-one else appears to share my problem, so I
guess it must be a set-up problem. But where do I start looking?