As for everyone else that is getting the FAIL-TOO-MANY error, just try marrat's solution in page 186, which basicly implies that you have to have another phone at hand and nitdroid installed on your N9, then register whatsapp on you other phone, then put your sim back in the N9, boot nitdroid, install whatsapp from play store, start registration and as soon as you get the confirmation SMS, just disconnet from the internet to prevent whatsapp from confirming the registration, write down the code, turn off nitdroid, boot MeeGo, run wazapp, when you get fail-too-many error again, press enter code manually, and use the confirmation code you got from the SMS on the nitdroid whatsapp app. It should work.
Personally, I just think, it's easier to register in any other phone's whatapp (a friends/family phone), and then when you get the SMS confirmation, just disconnect the internet connection before registration completes, write the code.down somewhere, and then use that confirmation code manually on wazapp rather than doing the whole other phone and nitdroid process, anyway, whatever works. Hope this helps.
oh, and please try to use the search feature before posting the same questions over and over again.

cheers!!