i am taking that as an example bug, it was in 6.1 and i also beg to differ on this bug, but only last week i downloaded and installed upgrades of 6.1.2 and patches and i had to run the upgrade again as posted in the Upgrade Instructions from 6.1.1 to 6.1.2
<p>
NOTE: After running upgrade script please check your site homepage. If you have errors on the page like missing language strings, e.g. '_day_of_1' on events or blogs block, follow the following steps:

a) Open the file file upgrade.php see more in editor.

b) Remove following line: .......
execSqlFile( './upgrade.sql' );
c) Find the line:
$iLangID = (int)db_value( "SELECT `ID` FROM `LocalizationLanguages` WHERE `Name`='English'" );
Replace 'English' with 'en' in this line.
</p>
<p>
that is direct off the 6.1 to 6.1.2 patch
would it not be better to just changes it in the file from the outset?