Had anyone tried to install an update from an non official source?
Depends on country/region where you live. Teamandroid contains updates for Indian market. Certain updates were not available in some regions, for example in Europe there were two November updates while in India only one. Therefore build number for December update released in India is different to December update released in Europe. If you install an update not intended for your region/country you will stuck on it and won't receive OTA updates further because of failing update pre-conditions.
It looks like you're new here. If you want to get involved, click one of these buttons!