Uh, what's TGP?

Where did you buy the tires from? If from an LBS do you know how long they had them in the store? "New" tires can age and get dry and have ozone type effects if stored too long in bright daylight locations. Store tires like wine, in a dark celler with nice humidity (from what I've read).

I've got a nice set of Nokian studded MTB tires in the garage with many cracks on them due to summer storage in the garage. Too bad because they look almost new otherwise.

If you did buy the tires at a shop maybe ask if they know how long they had them in the store. Just a thought.