Hello,
Just tested:
1. Server on Win 7, SDP on XP, Client - Nokia N72 (3 times connecting and sending file) - all works
2. Server on XP, SDP on Win 7, Client - Nokia N72 (3 times connecting and sending file) - all works.
Can you send me your code which reproduces the problem?
By the way, server is designed as it "disables" SDP record when client is connected. After client disconnects it "enables" SDK back. It is because one server can accept only one connection. To be able to accept more than 1 connection you have use more than 1 instance of the server (it is because of Channel number and related to some stacks).