Had to make some changes, because while in the Drippy Cave, I was seeing the Echo Echo canyon map.
So I created a map for Drippy Cave, and then played with the priorities and availablerects for both maps until they worked correctly.
Here is the whole Greater Faydark map section from the core_mapstyles.xml file.
Code:
<ImageStyle Name="exp03_rgn_greater_faydark_0" zonerect="-1135, -1677, 1686, 1598" heightmax="85" availablepriority="5">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_greater_faydark.dds" SourceRect="0,0,436,506"/>
</ImageStyle>
<ImageStyle Name="exp03_rgn_greater_faydark_1" zonerect="-288, -1150, 638, -111" availablepriority="4" availablerect="-288, -1150, 638, -387">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_greater_faydark_newbie.dds" SourceRect="0,0,436,506"/>
</ImageStyle>
<ImageStyle Name="exp03_rgn_greater_faydark_2" zonerect="-627, -62, -18, 655" availablerect="-640, 0, 13, 563" heightmin="85">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_kelethin.dds" SourceRect="0,0,436,506"/>
</ImageStyle>
<ImageStyle Name="exp03_rgn_greater_faydark_3" zonerect="-627, -62, -18, 655" availablerect="-615, 224, -479, 335" heightmin="70" heightmax="85">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_kelethin.dds" SourceRect="0,0,436,506"/>
</ImageStyle>
<ImageStyle Name="exp03_rgn_greater_faydark_4" zonerect="-627, -62, -18, 655" availablerect="-450, 300, -179, 510" heightmin="70" heightmax="85">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_kelethin.dds" SourceRect="0,0,436,506"/>
</ImageStyle>
<ImageStyle Name="exp03_rgn_greater_faydark_5" zonerect="-137, -450, 166, -93" availablerect="-137, -425, 166, -93" availablepriority="3" heightmax="-20">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_greater_faydark_echo.dds" SourceRect="0,0,436,506"/>
</ImageStyle>
<ImageStyle Name="exp03_rgn_greater_faydark_6" zonerect="-180, -521, 17, -294" availablerect="-180, -495, 14, -294" heightmax="-26">
<ImageFrame Name="imageFrame" Source="images/maps/map_exp03_rgn_greater_faydark_drippy.dds" SourceRect="0,0,436,506"/>
</ImageStyle>