Distributed Transaction Help

I try to use disrtibuted transaction. First,I use MSDASQL successfull:

set XACT_ABORT on
set ANSI_NULL_DFLT_ON on
set ANSI_WARNINGS on
BEGIN DISTRIBUTED TRANSACTION
select * from OPENDATASOURCE('MSDASQL','DRIVER={SQL Server};SERVER=192.168.2.1;UID=sa;PWD=PASSWORD;'). pubs.dbo.jobs
commit tran

Then I try to use SQLOLEDB, But failure:

set XACT_ABORT on
set ANSI_NULL_DFLT_ON on
set ANSI_WARNINGS on
BEGIN DISTRIBUTED TRANSACTION
select * from OPENDATASOURCE('SQLOLEDB','Data Source=192.168.2.1;User ID=sa;Password=PASSWORD').pubs.dbo.jobs
commit tran

I get the following error message:
The operation could not be performed because the OLE DB
provider 'SQLOLEDB' was unable to begin a distributed
transaction.
[OLE/DB provider returned message: New transaction cannot
enlist in the specified transaction coordinator. ]
OLE DB error trace [OLE/DB Provider 'SQLOLEDB'
ITransactionJoin::JoinTransaction returned 0x8004d00a].

but I run the code use SQLOLEDB without DISTRIBUTED TRANSACTION success:

select * from OPENDATASOURCE('SQLOLEDB','Data Source=192.168.2.1;User ID=sa;Password=PASSWORD').pubs.dbo.jobs

WHY? Please help me!is 192.168.2.1 the server you are executing from? You can't do this to the same instance of sql server.|||Originally posted by nigelrivett
is 192.168.2.1 the server you are executing from? You can't do this to the same instance of sql server.

Thanks nigelrivett! I executing the code each server,but get th same result!|||WHO KNOW WHY? WHO CAN HELP ME?|||I assume dtc is running and rpc allowed.
Is there a firewall between the servers.
Are they on the same domain.

I would suggest you post the message again.

If you do a search you will find a number of possibilities but there are a lot of things that can affect this.|||Maybe we can try downloading the DTCPing.exe file from the website below and executing DTCPing on both servers. The log file which will then be displayed will tell u what is wrong with the connection.

That's what i did and i found out my RPC was something wrong.
My error was "There are no more end points available from the end point mapper." Just that i don't understand what this error means.

http://support.microsoft.com/default.aspx?scid=kb;en-us;306843