From my own experience, turning off auto negotiate can lead to unusual behavior later on
I too had this crop up in an unusual manner .. the hardware was HP with Intel Pro 1000 on one side, and Cisco 65xx on the other. Neither side saw errors, and (most) everything seemed to work .. however, one java app that depended on SSL would constantly fail when it tried to retrieve a file. Both sides hard coded (didn't matter to what) wouldn't work. When we upgraded to GigE blades, it still wouldn't work in any hard-coded configuration, even though the O/S (Win2k3 .. RDP, FTP, etc.) appeared to work. Set both sides auto/auto : bam. problem solved. The app was Sonicwall Email Security (on the off-chance someone else is fighting that same issue). Cheers, Michael Holstein Cleveland State University