Tile's borders in Mobile XT

Hello,

I’m creating my gmapsupp.img for Garmin Mobile XT using following tools:
osmconvert
splitter.jar
mkgmap.jar

Result is okay, gmapsupp.img is created, routing is working well, everything is okay - except - when browsing the map and the zoom is quite far (I think more than 15 km), then there are rectangles on the map - probably the tiles have border…

The screenshot is here: http://famme.sk/xt/garmin_tiles.jpg

Is there any way how to fix this? I can’t find any parameter in the tools I’m using which can cause or prevent this…

Thanks for any idea…

-f-

Some devices show tile borders, usually there is option at device menu to enable/disable borders.

Well, I was looking deeply in all settings, but probably Mobile XT does not have this option…