Thanks for the help, Lexus have told me its not a common problem, im just unlucky and even more unlucky with the bill of:-
Parts £137.19 + vat
Labour 2.5 hrs £187.50 + vat (£75 ph)
plus im having the 60k service done while im at it, but they havn't told me the damage for that bit yet, i think they were being gentle with me.
BEWARE everyone, it may pay to carry a spare ignition barrel along side your locking wheel nuts just in case, as the problem strikes without warning.