DTC Error in SQL2008

Hi,

We are having issue with DTC and below is the error message.
Error:
SQLSTATE=25S12,Native error=-2147168242,msg='[Microsoft][ODBC SQL Server Driv
Distributed transaction error'
Error:
SQLSTATE=24000,Native error=0,msg=[Microsoft][ODBC SQL Server Driver]Invalid
sor state
Typical Errors in DTC Output When
a. Firewall Has Ports Closed
-OR-
b. Bad WINS/DNS entries
-OR-
c. Misconfigured network
-OR-
d. Misconfigured SQL Server machine that has multiple netcards.
Aborting DTC Transaction
Releasing DTC Interface Pointers

Ping and Telnet is successful between DBserver and app server using netbiosname.When tested DTCPing,it was sucessful from application to DB server but failing when tested from DB server to application server and error received during DTCPing was "Error 1722-RPC server is unavailable'.Network team also tested by opening 'any ports' and they could see traffic passing through but still application team was getting above error.Please suggest.