How to do away with this error for report manager?

There are 2 machines where we have deployed SSRS 2005 on Windows Server 2003 virtual machine.
I've created and deployed a very simple report (select * from table) and deployed it on both the servers.

On First server, it is working perfectly fine through
URL: http://<First>/reports (Report manager) AND
URL: http://<First>/reportserver (Report server)

On the second server
URL: http://<Second>/reportserver (Report server)  Works fine AND
URL: http://<Second>/reports (Report manager) , it gives me this error:
Execution 'r4gdacqymwzfkl45uuy3amij' cannot be found

I've checked with both the configurations and did not find any difference in their installation or configuration.

Onle one difference I saw is that on the Working Server, In the Configuration, the instance id shown was mssql.3 and on the server that gave me error, it was mssql.1
I don't feel thats the issue but just in case if it triggers any thought process, it will be helpful.

Just another difference is that, both the servers are in different domains.

Any pointers would be helpful.
Thanks