R2 Upgrade experience

Last week, I was performing an upgrade on existing BizTalk Server 2006 to R2. Phew... Though this was pretty easy...but I had to struggle a lot with it. The problem came in when I ran the installer and it showed only MgmtDb for performing upgrade. I checked out the Setup logfile and found that installer was unable to resolve the names for MsgBoxDb and DTADb (as I am not using BAM, BAS, Rule Engine & HWS etc..). I then went off with upgrading this onto a local system and noted down all the steps carefully, where the upgrade (as told by most of the people) was seamless. After banging my head with the issue, I just went across and checked the name for BizTalk Server Group in the Admin console and found it to be a custom one. This was the "Catch" :0) I changed this to "BizTalk Group" which was itself updated into adm_Group table in the mgmtdb and ran the installer...and "YES" .. the installer was able to resolve the db names for MsgBoxDb and DTADb this time :-).