During installation of Biztalk 2009 tonight I found that SQL Server 2008 R2 and 2009 are in fact incompatible - I couldn't ever get the BizTalk group to install as it was giving errors in the log like so:
2010-05-26 01:30:09:0039 [WARN] AdminLib GetBTSMessage: hrErr=c0c02524; Msg=Failed to create Management database "BizTalkMgmtDb" on server "SERVER01".
You will also get a message box with just a hex code of "0xC0C02524" as below:
I tried manually creating the database - but then it started to give errors with the stored procedure creation.
The below blog matches what I experienced during BizTalk 2009 Group Configuration: