Correcting moveto targetZ from floor level to head level. Explanation:

Client is giving floor level as targetZ but that floor level doesn't
match our current geodata and teleport coords as good as head level! 
L2J uses floor, not head level as char coordinates. This is some 
sort of incompatibility fix. Validate position packets (anc /loc) sends head 
level and usually we've assumed floor level.

L2_GameServer/java/net/sf/l2j/gameserver/clientpackets/MoveBackwardToLocation.java

@@ -81,7 +81,14 @@ public class MoveBackwardToLocation extends L2GameClientPacket
 		L2PcInstance activeChar = getClient().getActiveChar();
 		if (activeChar == null)
 			return;
-
+		// Correcting targetZ from floor level to head level (?)
+		// Client is giving floor level as targetZ but that floor level doesn't
+		// match our current geodata and teleport coords as good as head level! 
+		// L2J uses floor, not head level as char coordinates. This is some 
+		// sort of incompatibility fix.
+		// Validate position packets sends head level.
+		_targetZ += activeChar.getTemplate().collisionHeight;
+		
 		_curX = activeChar.getX();
         _curY = activeChar.getY();
         _curZ = activeChar.getZ();