1. This is a common but simple solution. This is a design issue. Results like this can occur in any program. The white type is dropping out because of the overprint option being enabled. The colour in the text can also alter do to the fact the underliing colour is not being knocked out. notice how the blue text changes to black because the red is still printing behind the text.

Solution:
Turn of the overprint on the problem type...The type should now print-out fine...