In SSP when you try to break blocks it seems that the server is way behind. It takes a few times to break blocks and when they do break it takes a while. I start getting Overload errors in my console stating that the server is running behind. I have talked with some other mac users and they seem to be having the same issue.

Attached are the errors I am getting:

[07:21:11 INFO]: Client> [07:21:11] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 3751ms behind, skipping 75 tick(s)
[07:21:41 INFO]: Client> [07:21:41] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 16588ms behind, skipping 331 tick(s)
[07:21:46 INFO]: Client> [07:21:46] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4801ms behind, skipping 96 tick(s)