distributed transaction error - help urgent

i have two remote servers connected to each other through the linked servers.

i can run querries or even perform inserts as far as its not inside a transaction
but when i am trying to run distribted transaction but it keeps on returning the same msg.

Server: Msg 7391, Level 16, State 1, Line 3
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].

i have configured the firewall, made sure the DTC service is started on both and enabled. they both have the same Sp packs, same config.http://www.experts-exchange.com/Databases/Microsoft_SQL_Server/Q_20888629.html

Go Google the error...there are probably a lot of reasons...|||1)are u using Microsoft Windows Server 2003 as OS? if it is,check this site,

http://support.microsoft.com/default.aspx?scid=kb;en-us;329332&Product=sql