20 months to pass all 4 sections before credit expires?

I hadn’t really paid attention to this at first, but I randomly saw the letter I got for passing FAR sitting on my desk and noticed that it says my credit expires on 9/30/2011. I took the test on 1/20/10….so that means that there’s a window of over 20 months to pass the other 3 sections before I lose the FAR credit (though really it’s 19 months I guess, since September is a “dark” month). Has that been the case for everyone? I thought it was only 18 months?

Also, I took AUD on 2/27 and passed it, and it has the same exact expiration date (9/30/11) as my FAR credit does, which I thought was interesting. So to me it looks like they say whatever date your 18 months falls on, they give you until the end of that window to pass the remaining sections before losing credit. Does that sound right? I always thought it was just 18 months from the day you took the test. Or is that just the case for my state (OH)?