I have problems with the '05 Pista hubs in general. The threads on the non-drive side of my hub were dinged up when I bought the bike. I recently swapped out the stock cog for a new DuraAce cog, and I noticed a curly strand of aluminum (presumably from the hub threads) came off along with the cog. Also, the cartridge bearings are about as smooth as gravel after only six months of riding. I'm not all that fond of the spokes and rims either.

I guess I shouldn't be too surprised. It's an inexpensive bike with some low quality components. The general rule applies: You get what you pay for.