Chain scratching

[iRob]

The lowdown - 2 month old Giant Anthem X2 with 650km.

 

When the shock is fully open and I ride front granny middle back the chain rubs against the front derailer. If the "pro-pedal" is on, no such problem.

 

Has anyone experenced this and WHAT was the cause?! Shock pressure too low?

 

Gear changes are perfect and the bike did this with like 50km on the clock. It has gotten a LOT worse in the last week.

 

HELP!!!????