The TTS must have caught a cold the day this was recorded!
You're right, and at the same time, if you hadn't mentioned it, I would have never noticed it… which means it's probably common place to approximate "-kl-" into "-kn-", simply because the tongue has to "travel a certain distance" to go from K to L, and in fast speech, there might not always be enough time to reach the perfect spot for L and the tongue might stop just a little earlier which happens to be the area where N happens. So there you go, my pseudo-linguistic explanation for this phenomenon. Not at all sure if it was satisfactory though! ;p
I am not sure if the computer has the same tongue problem you and I have. Is it possible to adjust the artifical voice a bit? I am practicing with a turkish student and she told me that my pronounciation sounds strange. after i presented her a few samples from the lessons, she confirmed that i started sounding like the computer. :-D