Well I write this because I had a annoying problem with my Arduino mega.
Many times I had the problem that I could not upload my scetch.
The IDE was uploading and in the end it just timed out...
Other versions of IDE didn't help me out here.
Other times it just goes well for a while. quite random...
I noticed, when it goes wrong, the 2560 just goes in reset for a small
moment and starts up again while the IDE is trying to program it.
My feeling was that it was a timing problem where the 2560
comes out of reset too soon.
I've put a 220nf capacitor in parallel on C12 (the capacitor between
DRT and the reset of the 2560) This solved the problem for me.
No more disconnecting the USB. It just runs fine now.
Maybe this can help other people to. I've seen a lot of people
on the web having the same problem.
Regards, Roland