Serial monitor giving out strange values

Hi, Serial monitor was working with with serial.print up until a couple of days ago, now it's not even giving out numbers for some reason. I have tried reinstalling but am still getting the same no matter what code I use, even example code from this website. The code we have been using is definitely working ok on my friends Ardunio and computer.

All I get is:

"��q0"�q"�a0��#����q0"�q"�a0"P`ӂ��q"��ӂ�0"�q"��a0"

I am currently running the latest Arduino software with an uno on Mac OSX 10.10.

Any idea what this could be?

Does the baud rate of the sketch match that of the monitor?

Yes, I've tried changing it around a few times too just in case but it's still doing the same thing.