TFTP server not responding on Windows 7 x64 Ultimate

I have tried to upgrade Cisco switch via solarwinds tftp server, but there is problem. Sniffing with wireshark shows that udp/69 request is going to my PC. But log in console doesn`t change. There is nothing. Trying to connect locally is successful ( tftp -i 127.0.0.1 get <filename>). Using tftpd from Fujitsu ServerView Suite DVD resolves this problem. Looks like everything working. But what happens whith my Solarwind TFTP Server? It suddenly stop working.