However, even after fixing this, I have still seen this problem (ADL_AD_RET_ERROR results) occuring.
Note that re-initialising the A&D Volume by calling adl_adFormat does not recover from this situation! 
When the A&D Storage Volume is suffering from this bug, I see adl_adFormat returning -8 (ADL_RET_ERR_BAD_STATE) - ie, it thinks there’s a subscribed cell.