Can't Play ISO files after Update to 2.4/5.3

Has anyone seen a problem with playing ISO files. I am getting this error:

"Playback error 
An error occurred loading this content."

I was able to play the ISO files before updating to aTV 2.4 / iOS 5.3 (I was running aTV 2.3 / iOS 5.2 before updating)

The files are stored on a Synology DS212j. I can play other types (mkv, avi, mp4...) from this device.

Any help would be greatly appreciated.

I have two ATV2 systems - one is currently on 5.2 with ATV Flash 2.3, and the other on 5.3 untethered with ATV Flash 2.4.

I have some ISO’s that give this problem you mention when I try to play them off my NAS - but that happens on both the above ATV systems.   Other ISO’s play fine on both systems.   That means any issue could be specific to some ISO’s rather than a generic problem affecting all ISO’s, so it could be worth raising a support incidence for your problem ISO(s).