Hello mm,
In other words, you've found that using the predicate Impressions >= 0 produces a different result than when setIncludeZeroImpression(true) is used?
What if you omit the predicate Impressions >= 0?
If you want all records including those with impressions equal to 0, please always set includeZeroImpression to true.
Cheers,
Thanet, AdWords API Team