NoClassDefFoundError

I am trying to invoke a third party API, which internally performs some native calls. I hit the following error and the JVM crash follows.

The classes "SomeClass1" and "SomeClass2" are present in a single jar file. I have set my java class path to use this jar. The point here is, SomeClass1 performs a native method call and throws NoClassDefFoundError in trying to find SomeClass2 (which is in the same jar)

Any hints on how I can debug this ?

java.lang.NoClassDefFoundError: xxx/xxx/xxx/SomeClass2
at xxx.xxx.xxx.xxx.xxx(Native Method)
at xxx.xxx.xxx.xxx.xxx(SomeClass1.java:55)
#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
# Internal Error (53414645504F494E540E43505001E8), pid=2440, tid=3568
#
# Java VM: Java HotSpot(TM) Client VM (1.5.0_09-b03 mixed mode)
# An error report file with more information is saved as hs_err_pid2440.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
Exception in thread "Thread-2"
[ April 28, 2008: Message edited by: Srikanth Basavaraju ]