Error with MB1A while budget check by using WBS element.

Hi experts,

Can anyone please me to solve problem with budget check by using WBS element.

I have assigned some budget to a WBS Element  and assigned the WBS element in WBS field in Additional tab in maintenance order. While creating the maintenance order budget check is executing properly.

But when I tried to withdrawing goods by using MB1A, I am error

Item 002 Order 4212979 budget exceeded

Message no. BP603

Diagnosis

Budget for WBS element /W-001 was exceeded by 1,570.25 INR in document item 002 Order 4212979 .

The problem here is, system checking available budget again at the time of MB1A, but the same amount already assigned to order.

How can I restrict budget check multiple times.

I tried CJBN Transaction. As suggested by Archana(http://scn.sap.com/thread/2006632) . But getting same error.