I have Michelin tires installed new in April 2013. Noticed this weekend that the left front tire is starting to show sun/weather cracks. Not sure why, as the MH doesn't sit parked for more than a coup...
Seems that's been a common problem with Michelin in recent years. I would check with the installer or Michelin to see about warranty replacement. No reason your safety should be compromised if it's a defect.