Yes, it is a bit worrying! @Globalti mentioned this kind of problem in a post earlier in the year. I like the ride quality of the latex tubes but I wonder if the subtle improvement over butyl is worth the potential problems?
I might give ultralight butyl tubes a go. Mind you, they could exhibit the same worrying characteristics.
How are the Veloflex standing up to use? How many miles have you done on them? Any cuts or other damage?Since giving up - regretfully - on latex I've been using lightweight butyl and they seem to offer a good compromise; they ride nicely with none of the extreme fragility of latex. However the best improvement in ride and comfort and overall "plantedness" in the feel of the bike has come from fitting a pair of Veloflex open Corsas, which can't recommend more highly, a truly excellent tyre especially in wet conditions. I will never go back to my old Michelin Pro 4s.