CountZero of the two failures, which occurred to me one, was on a 12 month old 'old' style post and the other on a 4 ride old 'New' micro post...
Common denominator for these failures and for one the other failures posted here was that they were 27.2 dia and had been ridden in cold weather failures seem to occur to the rear of the post where the head is bonded into place
As for the question of usage or stress one broke on Weavern Lane nr Chippenham and the other on the Canal path to Laycock
Despite getting a refund under warrantee for the 2nd post, I've not seen any one get an explanation from the importer or manufacturer
I really liked the I Beam system but, after having a 2nd one fail after 4 rides on nothing better than canal paths, I have extreme doubts about the durability of the head & post junction and if anyone is using these posts be alert for creaking noises as these proceeded both catastrophic failures