Check the server binding settings on the TFTP server and make sure that your currently available addresses and your binding list match your expectations. Then check your security settings and make sure that you are set to send and receive files and there are no restrictions set that might be blocking you.
Everything is currently set to bind with all IP addresses and everything is able to send and receive to and from all IP address. I even modified those settings to reflect the IP range that I needed under IP Restrictions, bound the interface (10.0.0.3) to the server, and also bound all ip's so it would use all the addresses in the list. Still no result. I have been letting this machine stay hooked up (it's just sitting on a desk in my office) for the evening to run and It has never responded to the switch's Read request.
Additionally, for good practice, I would only make one change at a time and I would stop and start the service after each change I made.