Yetiborg V2 problem

Hi, I bought a yetiborg V2 for my son this christmas but I cannot get it to work properly. The robot is assembled correctly and all 4 motors work - the canned sequence makes all the motors move in what appears to be the right order for the turns. However, when trying to move forward only the rear two wheels move and the front two are locked which means the robot does not move forward except in a very jerky movement as the front wheels prevent the robot moving. using the web UI, forward does the same thing as the canned sequence - the other controls are completely inconsistent though. reverse just makes the robot emit a whine, but it does not move. it will spin one way, but not the other. Follow me just doesn't work at all aside from making the yetiborg just jerk occasionally. I've connected a wii remote to the pi but although the example joystick control registers the remote as a joystick, pressing the buttons only makes a character appear on screen rather than moving the robot.

we are relatively new to the whole raspberry pi thing, and not experienced programmers, but I was hoping that the examples would allow him to work the robot so that he could then get into the programming side of it - but as it is it just doesn't work.

Am I doing something wrong? It seems odd to me that the movements the yetiborg makes with the canned sequence, which seem correct apart from only using 2wd for forward, do not match the movements that the web UI produces for what should be the same command.

It did occur to me that perhaps the examples file was corrupted during download, but reinstalling the software produces the same result.

Help please!