No such method error tells me it's a classloader problem.
You've got a class deployed twice to the JVM. One version has the method, the other doesn't. Depending upon which version the classloader loads, it may or may not call the class with the correct method.
Don't you love classloaders?
Here's a little article I wrote on
J2EE and WebSphere Classloaders, and the very type of NoSuchMethod exceptions you are talking about:
Understanding and Demystifying WebSphere and J2EE Classloaders I hope this help.
-Cameron