3dsmax 2015 SP2
Corona version: 1.00 DailyBuild Mar 26 2015
Noticed this behavior.
Started IR with VrayCamera+Corona Camera mod in viewport. IR starts and works correctly.
Closed IR.
Changed view from VrayCamera to Perspective. Started IR again but IR doesn't update now.
Closed IR.
Changed view again to VrayCamera. Started IR and now it works again.