You might run across the anomaly in the Countries report when you segment a country by Region.
As long as all rows are included in the display (no additional pages of results are available for that segment), you may see a lower total for Region than the total for that Country. (See example)
This is due to the IP address and the Geo database.
Some IP addresses may have a Country associated with them but the the Geo database may not have a more specific Region associated with them.
This will cause this appearance in the Reports.