Zones with no map

[Uggers]

In the Medium priority section above there's a mention of the cave systems in Antonica, so I thought I'd investigate; I had a look in the gnoll caves in the middle of the zone and saw no map came up, so I thought I'd make one. I did the locs, tidied them up, and only then did I look in core_mapstyles.xml for similar zones so I could test the map out before texturing it.
At this point I discovered a map called 'map_antonica_2_gnoll_cave.dds' which seems to be exactly the required map, created by SaintPeter.
The entry for it is as follows:

<ImageStyle Name="antonica_2" displayname="Antonica Gnoll Cave" menugroup="Karan" zonerect="726, -231, 1031, 123" availablerect="750, -210, 1007, 70">
<ImageFrame Source="images/maps/map_antonica_2_gnoll_cave.dds" SourceRect="0,0,436,506" />
</ImageStyle>

It obviously isn't showing up, though - at least, not for me.
Any idea what happened to this map and why it isn't showing?