When the IIS Application server and the SQL data Server are not on the same computer, tere might be malfunctions of the transaction.

1.       MSDTC module setup

1.       Control panel-management tool-module service-computer-my computer-right clicking-properties.

2.       Choose MSDTC page, click on” use internal coordinator”

3.       Click the button:” security configuration” on the bottom

4.       Select:” allow network access”, “allow remote client”, “allow entering”, ”allow outbound”, “Authentication is not required”.

5.       For database server, “request verification of the caller” is available.

2.       Adding MSDTC.exe in the firewall of both sides is excluded, eg: McAfee

Command Line:  netsh firewall set allowedprogram %windir%\system32\msdtc.exe MSDTC enable

Distributed transaction has been completed. Please register the new session into new  Transaction or NULL Transaction.

Here are the method:

Middle tier server-control panel-management tool-component service-My computer-right clicking properties-alternate Transaction timeout into 0, or increase its time.

http://support.microsoft.com/default.aspx?scid=kb;zh-cn;834849