[dba-SQLServer] Transfering SSRS 2005 Reports To SSRS 2008 On A New Server

To all,

We have lots of reports on our current server using SSRS 2005, over the
Christmas period we had a new server and installed SQL Server 2008 and SSRS
2008.

Yesterday after a bit of reading up from good old Google I tried to move all
the reports across to SSRS 2008 I backed up Reportsever and
ReportServerTempDB from the old server using the COPY_ONLY and also backed
up the encryption keys.
I restored the ReportServer and ReportServerTempDB databases to the SQL
Server 2008, I then went into report server configuration manager and
restored the encryption keys.  I then opened a browser and entered the URL
for the reports, hey presto all the folders and reports etc were there, so
far so good.

Unfortunately when I now try to open any of the reports I get an error
message saying that the data source 'our_data_source' cannot be found.  It
looks like the data source name which on the existing SSRS 2005 had spaces
in has been replaced with underscores at some point during the transfer.  I
tried creating a new data source and pointing a report which I was testing
to the new data source, but when I ran the report I still got the same error
message.

Has anyone came across this before, if so any ideas on how I can rectify
this ?

Many thanks in advance for any help on this.

-- 
Paul Hartland
paul.hartland at googlemail.com