1. In a data processing environment where a client requests a server to perform part of its processing, a method of updating said client's version of server-related client access data, comprising steps of: receiving, at a control point server, a first request from said client requesting that server-related client access data be transferred from said control point server to said client; and in response to said first request, sending said server-related client access data from said control point server to said client, along with a unique bind token identifying a version number of said server-related client access data such that each time said server-related client access data changes a new unique bind token is associated with said data, wherein said client uses said server-related client access data to form a second request for said server to perform part of said client's processing, and wherein said client sends bind token to said server as part of said second request, wherein, upon receiving said second request said server performs steps of: checking whether said bind token received in said second request is stored in said server's local store and is marked as valid; and if said checking step determines that said bind token is stored in said server's local store and is marked valid, scheduling said request form execution within said server, wherein said server performs further steps of; if said checking step returns a negative result such that said scheduling step is not reached, checking whether said token is marked as invalid; and if said token is marked invalid, returning said bind token to said client as part of a reply thereto.