There is a note in section B.1 of the camera's user's guide that says:
Unforunately, RS-232 uses inverted serial (high voltage means 0) but the Wixel only supports doing non-inverted serial. Unfortunately I did not notice that note yesterday, but I did tell you at a late stage that we hadn't confirmed whether the camera uses inverted or non-inverted serial and this could be an issue. I wish I had warned you more clearly that this might be an issue.
I think that to make the Wixel work with this camera, you will need some way of inverting the signals. You need a circuit that outputs 3.3 V when given an input of 0 V and outputs 0 V when given an input of 3.3 V. You need two of them in order to do bidirectional communication. You can make such an inverter using a MOSFET and a pull-up resistor. We have two MOSFETs built into the Wixel Shield that you could use to make the inverters. Alternatively you could get an IC that has 2 or more inverters in it, such as this part from digikey:
I think that IC would work for you but I haven't read the datasheet thoroughly enough to be absolutely sure.
You said you have an Arduino Uno. The NewSoftSerial library for the Arduino supports inversion, so you could try to use that to communicate with the camera. Please remember that unless you find out that the camera's RX line can tolerate 5 V, you will need to have a voltage divider between the Arduino's TX line and the camera's RX line.
I think you should bring all your stuff in to LVBots next Thursday. If it's working by then, you can show us what you've done. If it's not working, we can probably help you figure out what is going wrong.