Samueldw,
I noticed in your earlier post that you had mentioned the use of the 8u2 chip and I am pretty sure the 2560 is using the 16u2. May help may not but anyway it is generally good to know. Also, I have not found any good information on resetting the 16u2. I believe mine (16u2) is bricked but haven't completely thrown in the towel yet, whats more I have not been able to determine the reason why it is no longer working. I must admit that locating complete information on the 2560 is a bit like tracking down "Big Foot" in a snow storm...occasionally you can find a foot print but "Big Foot" always seems to get away...