There are 2-3 bugs with this .cap. First, make sure you test with chrome.
BUG 1 - Keyboard control problem
Run the .capx, click and hold down the left mouse button, and make sure to drag the mouse a bit afterwards - the bug doesn't happen if you only click without dragging. Then, without releasing the mouse button, press w, a, s or d to move the circle. Most of the time, there's about a half second delay before the ship actually moves.
Release the mouse and key to 'reset' the bug, as it won't happen again until they're not pressed. Try again, this time moving the ship diagonally. The second key pressed works immediately, as the bug hits the first key pressed after the mouse is clicked and dragged.
Occasionally the ship continues moving in a direction when a key is not pressed as well. I'm not sure how to reproduce that, though. Just moving around, changing directions quickly and clicking a lot often does it, and the ship only stops if you press the direction its moving in again.
BUG 2 - Firefox and IE don't display anything
Switch the preview browser to IE9, run it. Nothing appears in the window. Firefox doesn't display anything either.
BUG 3 - IE sometimes doesn't open
Also, after closing the IE window and rerunning the .capx, often IE doesn't open. It might be unrelated, but I also somehow got it to open chrome when IE was selected for the preview browser.
Might be something quirky with how firefox is in an unconventional location on my computer, though (it was moved from its original install location), resulting in C2 being unable to preview in firefox.
Vista, 32 bit, Nvidia 9800GT.