I actually own an XXL for myself (I liked the IQ routes and lifetime maps and really never used advanced features of other GPS units - except for that one case where you are going to a campground and all they have to give you is a Lat/Long to get there). I'm impacted by this bug as well. I bought my wife one of the new VIA units for Christmas, and the MyTomTom is a huge step backwards.
I write software for a living, and I'm damn good at it. I would NEVER try to expose a hardware device via HTTP. I understand some of the 'marketing' pressures of having something 'web based' or 'cloud' or fill in the buzzword of the day. I also see developers thinking this is a really cool way of abstracting all sorts of functionality - if you write a low-level interface that has an HTTP face on it, all sorts of interesting functionality can be added to existing devices by pushing out an update of the TomTom website (JavaScript that hits the HTTP port of the driver is likely part of the myTT website), and updates to the PC software (which is MUCH more complex to update than a website) become a thing of the past.
I did not do any analysis at all on how the whole thing is put together, but watching MyTomTom work made me wonder... Did the TT developers fully consider all 275 security software packages out there that may restrict hosting a port? Restrictions in the browser that may prevent certain requests across frames. Multiple browsers, and versions of those browsers, all running a billion addins. Malware in the browser. Malware written by individuals hosted on random websites could conceivably 'guess' the port a TomTom is listening on and do bad stuff. Hopefully, they are only accepting connections from the loopback adapter and even then there should be some level of communications security. Can you upload a POI file to the device w/o being logged into the MyTT site? I'd hope that you can - but that means there can be no real security on that connection with the device....
Oh, the fact that you can't own more than one TomTom device per email address? That's crazy. Oh, and it doesn't tell you in MyTomTom that by associating with a new device you lose the existing one. It tells you that in TTHome when you then attempt to update your other device. So, I had to create a new account using a different email address and associate the XXL to that one. Does anyone want to bet that come spring I will not be able to get a free map update because of this?
TomTom should have had FOR YEARS synced favorites across devices in a household. Why not the ability to grab a contact list from Outlook/Gmail/Yahoo/etc. and keep it up to date as a POI set?
Why does the XXL ask me EVERY MORNING "There are carpool lanes on your route. Would you like to avoid the Carpool Lanes?" WHO THE HECK talks like that? Certainly the distracted driving disclaimer guy didn't approve that one! Why not "Use Carpool Lanes?" Fifteen words vs Three. Double negative questions on mornings without coffee vs simple yes no question (tell me you can answer that question without several neurons firing).
Sorry for the rant. I think I was somehow baited into it
Don't get me wrong, I love the directions that I get out of the TT. IQ Routes, quarterly maps, user map corrections are all things that I did not see in the competition. They are easy enough for others to implement, however. You damn near have to be a software engineer to bend the TT device to the needs of the user. It shouldn't be that hard. Ever.