Difference in mb51 and mb5L report

Hi experts,

I have taken report from BI for 31.05.13 and have the following observations;

1. BI report (closing balance) is matching with MB51 (Opening+Receipts-Issues) but MB5L is not matching (selected for previous period i.e. May13)

2. Found that MB5L is not considering special stock.

Please suggest how to tally the BI output (or MB51 output)  with MB5L for the same selection period

thanks in advance