Vendor Isssue- Vendor Takes too much time to display

 Hi,

We have a vendor that is used to create invoices through interface.so far there are 700K invoice against the same vendor. There is no issue to create the invoice. But when trying to create an invoice or credit memo manually even after putting the entire vendor name it takes 3-4 to to move the cursor from vendor name field to vendor site field. This happens ONLY to this vendor. and again when we put negative amount in the amount field also it takes some time to move to the next field. We could not find any set up issue with this