It just doesn't make any sense honestly. The tags update fine, and the art will update if you don't change the screens, so obviously it's not a matter of RR reading the info. Maybe something in RR v.12/06/07 (and prior?) that doesn't allow the indicator to update?
What about setting up a custom indicator in exectbl.ini? Maybe
Code:
"MAINART","$songpath$folder.jpg"
Not sure if the above code will work or not...
Or something to that effect.
That way the indicators are independent of each other and thus will update independently...