Authentication issue with PAM on solaris 10

[Shirode, Sangita \(Sangita\)]

Hi all,
 
I'm using Tomcat 5.0.28.
I have a servlet which takes the Solaris system user id and password and
authenticate it with PAM functionality provided by Solaris.
My servlet calls the native method which eventually calls the
pam_authenticate Solaris system function to authenticate the system user
id and password.
The authentication works most of the time but fails intermittently on
Solaris 10. I observed this problem after I browse some pages in web
interface but there are no specific steps to reproduce it. Some times
this problem gets resolved on its own after certain period of time. But
the immediate workaround is to restart tomcat.
 
This problem does not occur on Solaris 8 with same setup.
 
Does any one ever faced this issue?
I' would appreciate your response on this.
 
Thanks and Regards, 
Sangita