Hello zzs2519,
(is that your real name?

)
I was able to reproduce the problem you reported. The steps you took were correct.
The liferay bundle that you are using (LR 5.2.3 with tomcat 6.0.18) is one that we had not tried before.
Anyway... invariably these incompatibility problems are simply due to classing jars - that is, clashes in the jars being used globally by the servlet container and the KonaKart webapps.
As it happens, I found that if you make the konakartadmin.war using the option for jbossliferay the war that is produced will deploy ok in your LR 523 TC 6.0.18 bundle.
So please try this:
ant make_admin_liferay_portlet_war -Djbossliferay=true
Deploy the konakartadmin.war that is produced in the way you tried before. You should see this:
11:56:46,245 INFO [DialectDetector:97] Using dialect org.hibernate.dialect.HSQLDialect
Copying 1 file to C:\liferay-portal-tomcat-6.0-5.2.3\liferay-portal-5.2.3\tomcat-6.0.18\webapps\konakartadmin
Deleting directory C:\liferay-portal-tomcat-6.0-5.2.3\liferay-portal-5.2.3\tomcat-6.0.18\temp\20090914115638324
11:56:49,402 INFO [PortletAutoDeployListener:87] Portlets for C:\liferay-portal-tomcat-6.0-5.2.3\liferay-portal-5.2.3\deploy\konakartadmin.war copied successfully. Deployment will start in a few seconds.
<snip>
11:57:09,724 INFO [PortletHotDeployListener:227] Registering portlets for konakartadmin
11:57:10,350 INFO [PortletHotDeployListener:346] 1 portlet for konakartadmin is available for use
If you haven't already seen it, there are a few other instructions for running the Admin App in Liferay in the Installation.pdf document under custom/konakartadmin_portlet/liferay/doc
Please let us know how you get on!