The following new key functions have been added for SilverCreator v2.0b3:
TABKEY
UPKEY
DOWNKEY
LEFTKEY
RIGHTKEY
SPACEBARKEY
The function returns true if the respective key is held down. They work like the existing functions SHIFTKEY, OPTIONKEY, etc. This means you can check if the space bar is being held down in a timer, and then fire the gun, instead of relying on the inaccurate/dodgy Key Down event.
Note that the Key Down even will still fire if you press any of those keys (Tab, Space, Up, Down, Left, Right). You will need to rewrite your code to move the key check from Key Down, and into your timer.
These keys were chosen because they generally have the same position on all keyboards (German, Japan, etc). Other keys are harder to support because they change positions.