chan

Hi all...

Environment
OS : Windows 2000 Advanced Server(SP4)
SQL Server : Microsoft SQL Server 2000(SP3)
DB Accessing : MSDTC, ODBC, COM+(VC++) calling Stored Procedure through
firewall

i have four databases, each size are 8G, 400M, 18G, 500M
there is a firewall between COM+ Server and SQL Server

so, i have configured port configuration for MSDTC as recommended by
Microsoft Support site
http://support.microsoft.com/kb/250367

almost for the past 1.5 years. my com+ application has worked 99.9999% fine
but from about a month ago i got this error at every particular NIGHT
time(ie. 22:00)
on particular database

[Microsoft][ODBC SQL Server Driver]Timeout expired
Com Error : DESC-->[Microsoft][ODBC SQL Server Driver]Timeout expired
MSG-->OR_20001_SN_ReceiptOrder
IDispatch error #3121 Error Count:1 GetLastError Number:0.

once this error occurrs, all other components which are using "transaction"
get the same error over and over and over again till i restart MSDTC service
or
SQL Server Database.
really strange thing is that this error NEVER occurrs at a daytime

i found the fact that sp starts and never completed after tracing by using
query profiler

is this related to network resource or table locking?
has anybody seen this case? or any ideas?