Today saw the arrival of a wee message in my Inbox from none other than Mark "I Made Blitz!" Sibly (I'd dropped him a line as nobody seemed to be able to help with my dilemma). Essentially, using certain gadgets, such as checkboxes and buttons, meant that the keyboard focus was lost (and thus, none of the keys would work).
The trick was to use the ActivateGadget command to restore keyboard focus but, rather than call this every frame (as I was doing, to no avail), the command was called only if a button or checkbox was manipulated. After 5 minutes cutting and pasting, full functionality was restored. :)
