Sony :: Lightweight Carbon Fiber = Fragile Casing

We run multiple Sony units that are light weight and supposedly made with carbon fiber casing or something like that . (TT, TZ, previpus Z) We also run other brands including netbooks and other laptops in the sub 3 lbs range. (Acer, Asus, Dell etc )

In the inevitable bumps of daily use and travel, I sometimes drop the case or even the bare notebooks. All of them survived beautifully.

Yesterday however, my shoulder bag slipped out of my hand and fell about 18 inches. The TT was inside that padded bag . Took it out and there was a nice two inch long break in one corner. It is beyond just a small hairline crack. I was astounded as my other laptops have survived much worse. (i.e. An Asus netbook fell out 30 inches without case on one corner straight onto the asphalt and only suffered a scratch etc.)

The damage to the TT case is far worse than any other laptop I have had through the past 15 years and it was a very minor fall in a bag.

My read then is that these uber lightweight designs by Sony are not very tough in terms of casing? The rest of the notebook functions fine and i won't be repairing it though I have four year Sony accidental coverage on it. I figure I'll use it until it really needs a hardware repair down the road.