Blue border in region map

[archaeous 0]

Whenever I save a large city 4km x 4km in the region map i get a strange blue border on the bottom left side of the city.  At first I was making my own custom region and this popped up so was thinking something wrong with what I did.  Opened up an existing default region.. In the picture it is berlin.  Opened an empty 4km x 4km city raised terrain a tiny bit near center of map and saved it.

The blue border appeared 

 

This doesn't seem to affect the gameplay at all and only appears on 4km x 4km tiles

I am running Windows vista and sc4 deluxe.  This is just very strange as it appears no matter if it is land or water, is always the same width and appears 100% of the time after saving.

[CaptCity 4,670]

This usually results from rendering maps at a resolution of 1600x1200 or above. But this looks like the game's default Berlin region - is it? You might try lowering the game's resolution, entering and saving each affected city, then reset to your higher resolution.

[Vandy 110]

Again, CaptCity, thanks for your help.

Regards,

Vandy