Upgrade from Joomla! 2.5.7 to 2.5.8

I've run through the upgrade instructions for Joomla!

http://wiki.bitnami.org/Applications/BitNami_Joomla!/How_to_upgrade_your_BitNami_Joomla!_Instance

I ran into a few issues with connecting to the database that were not clear in the documentation, but I've finally moved my Joomla instance to the latest Bitnami stack. However, once I logged in, I found that the Joomla version is back to 2.5.7 rather than 2.5.8. Does Akeeba overwrite Joomla and not just my data?

Thanks,

Jim