I thought that Area 51 discussion was a meta site for Area 51, and therefore users should have the same amount of reputation on both of them. Has my Area 51 discussion account gotten out-of-sync with my Area 51 account? Or is there some other reason why my two accounts have a reputation that don't match?
Meta rep should sync with main site periodically. I forced that sync for your account and now your A51 Discuss reputation matches Area 51.
Turns out that the service that runs scheduled tasks on A51 meta has been broken for a while...
Spot anything weird in the URL? It's no longer discuss.area51, but rather area51.meta. Nick Craver fixed up the scheduler config, and all scheduled tasks should be running correctly again.
We have plans to replace the current scheduler with a service that doesn't fail quite so silently, but there's no (•_•) ... ( •_•)>⌐■-■ ... (⌐■_■) schedule for it being deployed yet.