Hi,
Only thing I can guess is that when you uploaded the files they did not all make it.
For the blog the first script it should have run would be located at
/Setup/applications/blog/SchemaInstallScripts/mssql/0.0.0.1.config
Then it would run the rest of the scripts in version order from the folder
/Setup/applications/blog/SchemaUpgradeScripts/mssql/
So it seems it never ran that first script (possibly it was missing on disk) and now its a messed up partial install that may have run the script
/Setup/applications/blog/SchemaUpgradeScripts/mssql/0.0.0.2.config
and then it failed on the next one and cannot proceed with the rest of the scripts.
The only solution I know is
1. Upload the /Setup folder again and make sure all the files make it.
2. Manually delete the stored procedure mp_Blog_DeleteBySite if it exists as it would have been created by the 0.0.0.2.config script
3. Delete the row for the blog from the mp_SchemaVersion table
4. Visit /Setup/Default.aspx again and hopefully this time it will run all the scripts in sequence.
Hope it helps,
Joe