I don't think it's fixed. I just tried to send you more than 1 karma. The first one got through, but the second gave me an error. I have been facing this issue for quite some time. At first, I thought it was like a feature, rule, or limitation for lower ranked members. I always wondered why some legendary members are saying +3 or +2 in their posts. I mean, why would they do that, since one could only send 1!
The rule is that only 1 karma point can be given to the same user in 10 hours. There is certainly no quantity limit, you can give 1 karma point to ten different users. The problem being discussed here is something entirely different.
Moderators are exceptions and they can give more than one karma point to the same user without a time limit. That's why you see it +2 or +3.
By the way, the problem from the first post seems to have disappeared, it hasn't happened to me in a long time.