Because Microsoft's timeserver remains shit as ever (which is why if I install Windows I tend to sync up with nist.gov instead of windows.com, but this time I forgot to do so), the time/date stamp didn't match up and Firefox absolutely refused to sync. HOWEVER.... the only reason I found this out is because I checked about:sync-log and am able to correctly read those logs and the implication therein. Which, honestly, shouldn't be needed. When I realized this I synced up with nist.gov, which solved the sync issue, but if you don't know about the state of the Windows time server and how drastically synced up in regarding the time you need to be for the Firefox sync to work, you're pretty much screwed. Which is why I'd like to suggest a warning in regards to this, if the system notes a 'time de-sync' and tells you why syncing doesn't work. You shouldn't need (by the average citizen's standard) need intermediate or better computer knowledge skills to realize why the syncing doesn't work.