What is this captcha?!?!

Here is a quiz. What do you think this captcha is?

I spent around 15 minutes trying to get though the car service order online form, no “try another” option and at the end I just had to dig out their email and send my “manual” order.

Clues: it is not ZOXTKP, NOXTKP, Z0XTKP, N0XTKP or any of the small caps combination of the previous.

And this is the only captcha their web site generates. I’ll find out what it is tomorrow and post an answer :):).

Posting it under API design tag :):) as this is just an example of a stupid human API, either mine or theirs :):).

Few links connected to CAPTCHA guidelines:

http://caca.zoy.org/wiki/PWNtcha, http://bitland.net/captcha.pdf, http://priyadi.net/archives/2005/04/13/captcha-guidelines/

[Update 7-Jul-2010] Okay, this turned out to be a bug of a captcha generation. Real one should be (and is) looking something like:

At least it was not me silly!!!