Yup I've had problems when restoring. It went into that infinite loop. where iTunes would keep asking me to restore my phone to a previous backup, or as new. If I selected previous backup, that is where the loop occurred. When I setup as new, the problem went away. So much for trying to restore a backup.
I am using a PC, running Vista Ultimate, with a 3G 16GB iPhone.
I got stuck in a loop as well. My phone was in recovery mode but the restore would end before finishing leaving my phone in recovery mode. Oddly enough switching USB ports seems to have fixed the problem. Before you ask both the failed and successful USBs are 2.0 so I have no idea why one worked and the other didn't.
Does it count if you had problems restoring when you are trying to jailbreak? I used winpwn to jailbreak my V1 and it wasn't working right, but i had gotten to the point where it was at the slide for emergency screen and had to restore to the regular firmware, but that wasn't working right.
Ok, so I just looked over the poll results and it seems that windows problems with restoring/updating the phone are 3x more likely than restoring/updating with macs.
But, after doing some thinking about this, i realized that there are probably 3 times as many windows users than there are mac users. Which would mean that it's a wash. For every 1 Mac problem, there are 3 windows problems. Which makes sense since Windows is the more "mainstream" operating system.
Please keep voting! And thanks to everyone who has!