Was just about to start a thread but found this -- I am having a similar issue as well...
I direct added 8 folks, and my total user count didn't change. Searching doesn't find them, but I can't add them again or I, too, get an error that they are "already members".
As an additional test, I removed my work e-mail address and re-added it. This, too, didn't seem to change the total user count, but it does appear in searches (and all seems to work just fine), so it's perhaps just addresses that were not previously in the group (which of course is most of them) that are susceptible to this bug.