When running non-atomic scoped database transactions across your network, getting schemas from the wizard does not seem to exploit this little known fact. You need to make sure that DTC is enabled on both the BizTalk machine(s) and the database you are connected to.

Objects to check for:

• In Component Services (Administration Tools) right click My Computer, on the MSDTC tab, click on Security Configuration Tabl and Allow Inbound and Outbound Communication.
• In Windows Components (Add/Remove Programs) click details of Application Server make sure that Enable network DTC access is checked.