Blanket Release that is created against Blanket Purchase Agreement via Buyer Work Center does not su

Greetings ,

     I have created a Blanket Purchase Agreement via Buyer Work Center and i have included a Line type as Fixed price Services (related to service procurement). After the BPA got approved i issued a Blanket Release against it , i have noticed that the only Document Style that supports the Release is Standard PO style. My Problem is that Standard PO Style can include a Fixed Price Service line type  but afterwards this line cannot be received via Work Confirmation, which is the way to receive the Fixed Price Services line type. so to conclude the issue :

1.    BPA is created and approved via Buyer Work center.