Expense items listed as Money In in a Category Report

This issue exists only if you are using the old Category Summary report. This report is one of the few remaining old reports that pre-date the current print engine and interface. In that report, a negative expense value (a credit or return) would trigger an expense category showing up as income.

I suggest you abandon any reports based on Category Summary, and instead use the newer Transaction or Summary reports on the Reports screen. You can build the same detail or summary reports, you actually gain new functionality in formatting -- and you won't see a negative expense listed as income.

(The developers have said they will eventually remove the old reports from he program; I suppose they haven't done so yet to avoid disrupting users who have saved reports.)