nah i'm pretty sure it's goo that got into the edges of the little plastic things with the cross that you push the key caps onto... i gotta stop eating at my desk...
the spare will be disassembled and the switches all will be soaked in alcohol for a few days and i have been meaning to do some slightly more advanced programming of the keyboard firmware... it's just quite a bit of extra stuff to learn, probably will be a day's work at least
currently, the keyboard has three layouts, the cyrillic depends on me switching manually to russian layout to work and it's clunky, there is a way to make the keyboard emit combination codes - have to be separately programmed for mac, linux and windows - that mean i don't have to change the keyboard layout... and there's some other more fancy bits of programming i have in mind...
anyhow, here is the new one:

still gotta try and figure out why some of the keys are getting sticked... starting to suspect a dodgy USB cable tbh