Did you cun the script to update config and registry? I did similar move last week on my BizTalk 2006 R2 server.
There should be a script and sampleupdate schema under the <drive>BizTalk Server… /Schemas/Restore
Check if you done the below changes.
1. After moving database to new server, ensure all the log in sercurite and previlages are same as old server.
2. make sure new server MSDTC accept in and out bound network transaction
3. Stop BizTalk applications, Enterprice Applications from services
4. Go to ProgramFiles/BizTalk server.. / Schemas/ Restore/SampleUpdateInfo.xml
5. Replace all SourceServer with your old db server name
6. Replace all Destination Server with your new DB server name
7. Uncomment the database updates in that file if u needed
8. run the following scripts from command prompt and make sure they are success
a. Run cscript UpdateDatabase.vbs SampleUpdateInfo.xml
b. Run cscript UpdateRegistry.vbs SampleUpdateInfo.xml
9. Restart ESSO and BTS applications, Windows Management Instructions
10. Remove the old group from BizTalk Admin conlose and select the new one from existing connections
11. Ensure all the database update are correct in BizTalk Config console
12. Update Receive port if you are using EDI Batching under the BizTalk EDI Application
Hope these will helps you,
Siva