Replication issues with SQL Server 2005 to SQL Server 2008 R2.

Dear Gurus,

I have a setup SQL Server 2005 with Windows 2k3 as a publisher and same setup for Subscriber also.
Now we are migration Subscriber from Physical box to Virtual boxes which has SQL Server 2008 R2 32 bit with Windows 2k8 R2.
Now issue is we have 3 instances one default and 2 Named instances

Deafult instances are working fine where as Named instances not able subscribe
Note: 3 Instance has different port numbers.

can any body help us to resolve the setup issues...

Thanks in advance

Thanks Hemant,

Intial level only I am getting issue which is saying Subscriber not available(that means Publisher in 2005 and subscriber in 2008R2 ,Problem with named insatnce only,we are able to Publish deafilt instances).

Default instances and 2 Named instance has diff Ports as well.
Note: All ports are open

Apology
Delayed to get Information

Cannot connect to Krole\rube
Filed to connect to server Krole\rube
A networkrelated or instance specific error occured while estibilishing a connection to SQL Server
The Server was not found or was not accessible.
Verify that the instance name is correct and that server is configured to allowed remote connection(Provider:SQL Network
Interfaces,error:26-Error Location Server/Instance Specific)

Yes,I am able to access the Publsher from subscriber and for testing from subscriber mechane I am able to Publish to subscriber(Publisher machane)
(it is working with revers direction).
to access the subscriber form publisher I have mention the port number (General check).But while configuring Replication Instance followed by port number not allowing.

Thanks in advance

Thanks Satya for your inputs