This is strange. I know that Impulse shows you the current available version, not your actual version. There was a recent issue where it wouldn't update the patch download status, even though it was downloading it, but I'm not sure if it's fixed or not.
In any case, you can always uninstall the game and install through Impulse (unless bandwidth is an issue) and it will always give you the latest version with no need to patch. You can do this for v1.09beta too, just check "show pre-release versions" in the blue orb menu.
Otherwise for 1.05, like StormReavan said, it is available as a standalone file on other sites.