Debian Configuration :: Accidentally Upgraded Squeeze To Sid?

I just noticed that I had a sid line on my sources.list, at the end of all squeeze lines, and I've been updating more or less regularly. Does the ordering imply some sort of "preference", so that the first lines are preferred over the subsequent ones, or is it all about the latest version?After removing that line, and taking a look at my installed packages with synaptic, all the "latest versions" of the packages seem to be the ones that are already installed, and I click on properties, and there are no older versions available, only "##.##-### (testing)". Emphasis on "testing", rather than "sid" or "unstable". Of course I didn't check all of them, but about a dozen, and none deviated from that pattern. However, I went to double check on the web pages about the packages, and it seems that many of the squeeze's packages are at the same version of sid. I couldn't yet find one that is not.perhaps the sole fact that the sid line was on sources.list is enough to know that something happened -- as I don't recall having ever set up those configuration files about preferred sources/pins or however it's called), and suggestions on how to proceed? My hunch would be to just downgrade things gradually as they eventually fail (as I did with geeqie, which is why I suspect that there is some mess), but leave everything alone. Not try to fix what is not quite broken. And if it fails too often, go full-blown sid.