Problem in material allocation in sales order

Dear SD Gurus,

I am creating a sales order with these details -

Sales Organisation - 1000

Distribution Channel - 10

Division - 00

Plant - 1000

Material - AM2-GT

in IDES

at first when I am trying to create the order then one error throws and says - material does not belongs to the sales area then I extend the material to that sales area

now again when i am entering the button after giving the plant name then this error comes - "Ship-to party 1171 not defined for sales area 1000 10 10"

Point 1 - customer 1171 belongs to sales area 1000 10 00 like the material also from same sales area

Point 2 - material is showing the error whether i give the plant or not

Point 3 - i cant understand the relation with the material and customer where both correctly configured to same company code 1000 and same sales area and plant

Kindly do the needful