Additional info: something that looks like my problem happened with a friend's laptop after installing Jupiter. Even without activating it, it seems like it changed something in ureadahead and then it became as slow as mine. After uninstalling Jupiter, the problem went away. However, I don't have Jupiter installed and this happens even in a new installation. Purging ureadahead and reinstalling it didn't change a thing either.
Additional info: something that looks like my problem happened with a friend's laptop after installing Jupiter. Even without activating it, it seems like it changed something in ureadahead and then it became as slow as mine. After uninstalling Jupiter, the problem went away. However, I don't have Jupiter installed and this happens even in a new installation. Purging ureadahead and reinstalling it didn't change a thing either.