Deficit of BA unrestricted use (Stock Allocation Issue)

Hi SAP MM Guru's

I am facing one Issue

Please help me to close this Issue

Business Process:

Industry type : Apparel & Foot wear, AFS Material.

Nov 1st 2013 i have created a Sales Order for Plant P1 ,Storage Location S1, for QTY : 10 (in MMBE stock is available )

Allcation is happened

Delivery is also completed

while doing PGI we are getting  Error : Deficit of BA unrestricted use (here in MMBE stock is not available )

my question is

At the time of PGI, there was issue of stock deficit, Pls check & confirm how system allowed to move the stock to other SLOC when allocation is already made for the free stock,.

Same issue is not happening for other plant…. ( Issue is with New Plant )

Please do needfull

Thanks & Best Regards

S kumar