I do too, but here in FL in the summer months, with the AC running constantly, my 722 temps averaged over 120 and peaked over 130, which is the tipping point when problems started occurring, until the ext fan solved it.
This is really old news. Most of us knew that 5 yrs ago! don't get addicted to watching your temps Its fruitless
I can tell you from personal experience it's not fruitless.
I get a 722K on September 2011. A few weeks later, it started freezing and rebooting, especially when I was adding timers.
I found this thread. I used a fan on the back left side and lowered the average temperature from 140 to now which is 95.
And I haven't had any problems since.
So either overheating is the problem or it's just a big coincidence.