single sign on problem with jcifs/NTLM

I have installed the NTLM authentication filter and singel sign on works fine 
the first time a user access my test servlet that calls the 
request.getRemoteUser() function.

But after one logon it seems like the sevlet locks, and no authentication is 
possible from any other computer in the network. 

After about 5 ´minutes the lock seems to disappear and connection is again 
possible from other computers.

any suggestions on what's wrong would be appreciated.

/G


web.inf


<?xml version="1.0" encoding="UTF-8" ?> 
  <!DOCTYPE web-app (View Source for full doctype...)> 
- <web-app id="WebApp">
  <display-name>NTLM</display-name> 
- <filter id="Filter_1077521517646">
  <filter-name>NTLM HTTP Authentication Filter</filter-name> 
  <filter-class>jcifs.http.NtlmHttpFilter</filter-class> 


- <init-param>
  <param-name>jcifs.http.domainController</param-name> 
  <param-value>xx.xx.xx.xx</param-value> 
  </init-param>

- <init-param id="InitParam_1088771054192">
  <param-name>jcifs.smb.client.username</param-name> 
  <param-value>xxxx</param-value> 
  </init-param>

- <init-param id="InitParam_1088771054193">
  <param-name>jcifs.smb.client.password</param-name> 
  <param-value>xxxxx</param-value> 
  </init-param>

- <init-param>
  <param-name>jcifs.smb.client.ssnLimit</param-name> 
  <param-value>1</param-value> 
  </init-param>
  </filter>


- <filter-mapping id="FilterMapping_1077521517646">
  <filter-name>NTLM HTTP Authentication Filter</filter-name> 
  <url-pattern>/*</url-pattern> 
  </filter-mapping>
- <welcome-file-list id="WelcomeFileList_1077374022597">
  <welcome-file>index.html</welcome-file> 
  <welcome-file>index.htm</welcome-file> 
  <welcome-file>index.jsp</welcome-file> 
  <welcome-file>default.html</welcome-file> 
  <welcome-file>default.htm</welcome-file> 
  <welcome-file>default.jsp</welcome-file> 
  </welcome-file-list>
  </web-app>