Sorry about the late answer. We have been meaning to try to fix this before answering, but then it just hasn't happened yet.
The reason is that we did not have any good source material. We did not have any region polygons, only county. So to create the region polygons we merged the counties into groups, which doesn't look good at all.
When we did this, there was no data in Openstreetmap which is our usual source for this. Nowadays there is, and it's on our todo-list for polygons to test an import for Portugal. We are hoping to get around to it soon, it's probably the second highest priority of polygons.
France is the one with higher priority, which we promised last week. But due to technical issues with Openstreetmap we had to abort/postpone.
UPDATE: New data has been imported and this should be solved within 2 weeks (waiting for cached data to expire).