Does the datasheet help you:
http://www.rev-ed.co.uk/docs/kit110.pdf
Do note from front page this is a stripped down version.
They are not too different to the other caps in another photo across IC power pins for filtering purposes.
you could try some 100nF poly caps or 10uF tantalum caps if no better answer received.
Looks (but that is a guess) from photos like they are just 100n monolithic capacitor for spike/switching filtering.
or
Do these videos help you? (cannot access videos from where I currently am located)
http://www.picaxeforum.co.uk/showthread.php?t=13209
Seems that Servo Magazine from September 2007 ran a construction article on the PICAXE micromouse. That might have a schematic or parts list if you search for a copy.
EDIT: once home had a look at the Servo Mag but is is just a reference to a forthcoming micromouse comp in 2007.
