Not actually the server software itself, but rather the mac_startscript.sh file. I've seen it in past releases, but maybe this will help some others to be aware. The script tries to start java with
#! /bin/bash
java -Xmx1024 -jar server.jar
but that just ain't enough memory. It helps to stick an 'm' after the 1024:
java -Xmx1024m -jar server.jar
If you want to just double-click the file in the finder, my favorite is to make it a command file, like start.command.
My actual startup file is:
cd ~/Desktop/RW_server_0.8
java -Xmx2048m -Xms1024m -jar server.jar
The name of the directory is wherever you chose to install it.
Be sure to make it executable, and you're all set. Use Terminal to find the file and then type:
chmod +x start.command
There's other ways to accomplish all this, but I'm just showing what has worked for me. 
