The problem with your implementation is that you have circular dependencies:
RS[VBGS,IDS ] depends on QBGSaccess[VBGS,IDS]
QBGSaccess[VBGS,IDS] depends on VBGSp[VBGS,IDS]
VBGSp[VBGS,IDS] depends on RS[VBGS,IDS]
and the cycle starts again and never gets to an ending. And that is why your recurrence happens.
Can you let me know how you solved this problem?, I would like to know what the stop conditions should be.