Notes/Domino 6 and 7 Forum : Domino 6 hanging on iseries

This is a brand new single server install of Domino 6.0 on iseries V5R2 - brand new box.
The server starts up ok but after 30 seconds or so the server hangs.

It will not respond to console commands or client requests. The iseries shows that server tasks are waiting for network operations to complete. The client sits there waiting for the server to respond (with the "lightening bolt" in the bottom left) but never returns an error unless the server is ended in which case the "remote system is no longer responding" error appears instantly.

In the course of investigations I've removed all the server tasks from the tasks= line in my notes.ini
The server then starts up fine.
If I load tasks manually everything runs fine to a point until there are more than 4-5 tasks running. At this point the server will stop responding within 30 seconds or so.

Interestingly the iseries navigator client "verify connection" utility also fails to connect to the iseries box during this time. As soon as the Domino server is stopped this can instantly contact the iseries again.

So, it seems that this is a problem with Domino tasks taking control of the IP stack and not releasing it. whatever has got control of IP will not release it until the Domino server is stopped. The iseries domino console is also frozen.

I've started different combinations of server tasks and there is no pattern to the problem, i.e. it cannot be narrowed down to a specific task being loaded. Any task can seemingly cause the problem once 4-5 are loaded simultaneously.

The server has had the following combinations of tasks running ;
adminp, router , calconn, replica, POP3, amgr, sched, update, colsrv400
As stated I have not been able to find a pattern as to when the server will hang so I cannot narrow it down to a particular task.

Whilst the issue is occuring there is plenty of CPU and memory available. This is a brand new very well spec'ed box.

At the moment I am running with only ADMINP and ROUTER. With only 2 tasks running the box has been up for 15 hours. It ran all the overnight tasks (design,etc) without any problems. Additionally I have been accessing the server for 3 hours registering users and performing general setup tasks from a client without any performance issues at all.

The box is not yet in production so it's not critical at the moment.

We have checked that we are up to the right PTF level and the documented requirements for 6.0 on iseries are all met. Nexxt Monday we will install 6.01 to see if this relieves the issue, but I've run 6.0 on other iseries boxes and that's been fine.

Any ideas anyone? thanks in advance for any responses.