Delving back in this forum I find several similar queries without answer.  Does Bowens not read this forum ?  Most manufacturers use their forums as a resource and an aid to development.  As an instance if I post a problem to Photo Mechanic there will regularly be a reply within 20 mins from the man who writes the programme - and when needs be he rewrites the programme.  I like that attitude.

Nope - I've substituted from a box of photofloods bought while they were still legal.  Strangely I got the kit out yesterday with all my switch cleaning and assorted stuff to tackle this problem and after an hour of being switched on at various levels with no sign of flicker I put it all away again.  Tried to replicate the conditions and settings from before but not a single "flick" .  Whilst that was nice I'm now wondering if I have one of those horrible intermittent faults.  The only thing which may have worked is that last time I applied some cleaner/conductivity fluid to the lamps threads and maybe just maybe it has worked in storage.  Other than that it is much warmer now is the only difference.