First of all, when you are on an ore prospecting mission the mission computer does not respond to you, so it's impossible to abort the mission from space.

From a station if I try to abort the mission, first I get the 'Are you sure?' box, and when I click 'Yes' I get the 'Connection Terminated By Server' message.

I experimented with this using three different characters and different ore missions as well, all yielding the same results.

I am using:

Mac OS 10.3.5
800 mHz G4
GeForce2 MX

Yeah, I found the problem and fixed it. Also,the prospecting mission has a chat interface now, so you can abort the mission, etc...