I am having issues getting Dynmap to load properly. I have tried version of dynmap 1.3 and 1.4. Below is the error I found in the BukkitForge log. I hope this helps in finding the issue. If you need more, let me know.
<record>
<date>2013-02-04T22:16:09</date>
<millis>1360016169152</millis>
<sequence>4078</sequence>
<logger>BukkitForge</logger>
<level>SEVERE</level>
<class>org.bukkit.plugin.SimplePluginManager</class>
<method>loadPlugins</method>
<thread>30</thread>
<message>Could not load './plugins/dynmap.jar' in folder './plugins'</message>
<exception>
<message>org.bukkit.plugin.InvalidPluginException: java.lang.IllegalArgumentException: Error initializing dynmap - bukkit version incompatible!</message>
<frame>
<class>org.bukkit.plugin.java.JavaPluginLoader</class>
<method>loadPlugin</method>
<line>204</line>
</frame>
<frame>
<class>org.bukkit.plugin.SimplePluginManager</class>
<method>loadPlugin</method>
<line>307</line>
</frame>
<frame>
<class>org.bukkit.plugin.SimplePluginManager</class>
<method>loadPlugins</method>
<line>232</line>
</frame>
<frame>
<class>org.bukkit.craftbukkit.CraftServer</class>
<method>loadPlugins</method>
<line>804</line>
</frame>
<frame>
<class>org.bukkit.craftbukkit.CraftServer</class>
<method><init></method>
<line>225</line>
</frame>
<frame>
<class>keepcalm.mods.bukkit.asm.BukkitStarter</class>
<method>run</method>
<line>46</line>
</frame>
<frame>
<class>java.lang.Thread</class>
<method>run</method>
<line>722</line>
</frame>
</exception>
</record>