Kelly Safari AWR Problems?

The tire tread and all on my Kelly Tires seems very good, but they are all starting to crack near the rim. The tires are form 2004 so they are about 3 and a half years old.
I am guessing maybe the previous owner never inflated the tires up to the proper PSI after off roading, and he continued to drive for quite some time.
Either that or the tires have a problem? Anyone know anything?

Thanks for any and all help.