Firstly, I don't think you should post the same post twice within such a short duration of time. And if done so accidentally, then please delete the other post.
Alright then, so you're using struts 1.3.8. You don't need a struts.jar because there's already struts-core-1.3.8.jar to do all that the struts.jar used to do. And all the things it can't do are packaged in the struts-extras-1.3.8.jar. So well, there's no problem with your "lib".
Now the only problem can be in your struts-config.xml. Perhaps there's some unintentional mistake that you might have missed out upon. I've worked in struts 1.3.8 and specifying a <message-resources> was never a problem. Your tag also seems to be perfectly fine. You might also want to take a look and confirm that your DOCTYPE declaration is pointing to the correct DTD.