SSRS Issues with 32bit and 64bit ODBC drivers - reporting-services

Question

The ultimate goal is for users to be able to run a report that looks pretty and grabs current information from our database. We'd like to use SQL Report Builder since we're already using it for other reports. The database is Cisco UCCX and we're accessing it with an ODBC connection from our reporting services SQL Server 2008 R2.
We've successfully setup System ODBC connections with both 64bit and 32bit drivers. When trying to access the connections though, we're receiving errors.
Using the 32bit driver, we try to create a Data Source in SSRS for use by Report Builder and receive the error:
"ERROR [IM014] [Microsoft][ODBC Driver Manager] The specified DSN contains an architecture mismatch between the Driver and Application"
Using the 64bit driver, we can successfully create and test the ODBC connection as a Data Source, but then when we attempt to create a Dataset with it in Report Builder, we get this error:
ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
Error received using the 64bit driver for ODBC connection

Answer 1

I ran into this recently. You need to have the same name for both 32 and 64bit DSNs. It's annoying because SSRS can run 64bit, but reportbuilder only exists in 32bit. So parts of reportbuilder seem to work (like running queries), but some don't (like refreshing query fields). Just have a DSN for both 32bit and 64bit, then make sure they're both the same name and the problems should stop.

Answer 2

You may be hitting an old but recurring issue with minor corruption in the Windows Registry.
The corruption takes the form of entries containing this 4-character string —
#=""
These entries aren't visible anywhere except Registry export files — the Registry Editor ignores them completely — but they can lead to a number of undesired behaviors, including the error you report.
NOTE: On your 64-bit Windows machine, there are naturally some complications tied to the 32-bit Registry. This Microsoft KB article may be sufficient to get you through these.
I suggest that you use the 64-bit Registry Editor (%systemroot%\system32\regedit) to export the following branches (where these problematic entries tend to be found) —
HKEY_LOCAL_MACHINE\Software\ODBC
HKEY_CURRENT_USER\Software\ODBC
HKEY_LOCAL_MACHINE\Software\WOW6432Node\ODBC
HKEY_CURRENT_USER\Software\WOW6432Node\ODBC
Edit these files in any text editor (Notepad or Wordpad are generally fine), and delete all lines which consist of that 4-character string, above. Then, delete the Registry tree segment(s) you exported, and import from the edited files — thereby restoring the tree segment(s), minus the corruption.
It won't hurt to repeat the above process with the 32-bit Registry Editor (%systemroot%\syswow64\regedit), but as you've described the issue, I don't think you'll find any #="" in the 32-bit export.