I have been using AVR Studio 4.14.589 with the mkII with no problems. To see if I could reproduce an .elf flash problem some others are having, I just installed the latest AVR Studio in 32 bit Virtual XP under Windows7 64 bit:
[Sweet cut and paste from XP to W7]
AVR Studio 4.16.628 GUI Version 4, 16, 0, 626 Operating System Major 5 Minor 1 PlatformID 2 Build 2600 Service Pack 3 Plugins: AvrPluginAvrAsmObject 1, 0, 0, 47 AvrPluginavrgccplugin 1, 0, 0, 10 Stk500Dll 1, 0, 1, 11
AVR Studio connected and wanted to upgrade the mkII firmware. When I said no and continued, it failed to read the target signature. The Dragon works fine in this setup so I guess the next step would be to let it change the mkII firmware.
My question is, what happens when I connect the mkII back to the older version of Studio. Will it work, offer to downgrade, or force me to go through a manual reload or upgrade AVR Studio?