Originally Posted by
merkaba22 
I started my download about 20 mins via wireless and then carefully plugged in my ethernet cable to decrease the install time which I have done successfully many times.
For some reason I wanted to ensure this change so I turned off the AirPort and got an error that the connection had been lost. hmmm.
In iTunes > Downloads, I saw the download had been halted and selected the "resume" but after nearly 75MB of prior downloading, the download for 3.0 began anew (without re-initializing the process)....
Funny thing, when I go back to iTunes > iPhone, the download button for (3.0), "Update", is no longer greyed out.
When clicked on, the update process begins with the APPLE SLA, etc. until it finally gives a -49 error message and stops.
When I check, the prior download is moving along nicely and when I go back to iTunes > iPhone, the download button for (3.0), "Update", is yet again no longer greyed out.
I tried it again and had the same experience whilst the download continues.
Just now, my iPhone just showed that a Sync in Progress message on the iPhone screen and by the time I finish this sentence, iTunes says the Apple servers are too busy to activate ....
The "Update" button is still active ... man.